Index of Diseases



Definition: Infection with nematodes of the genus HAEMONCHUS, characterized by digestive abnormalities and anemia similar to that from hookworm infestation. Annotation: nematode infect ID#: D006188

Haemophilus Infections

Definition: Infections with bacteria of the genus HAEMOPHILUS. Annotation: gram-neg bact infect; check text for species & index by instructions on species; MENINGITIS, HAEMOPHILUS is also available ID#: D006192

Hair Diseases

Definition: Diseases affecting the orderly growth and persistence of hair. Annotation: GEN or unspecified; prefer specifics; dis of hair follicles: coord IM with HAIR FOLLICLES (IM) but FOLLICULITIS is also available ID#: D006201


Definition: An offensive, foul breath odor resulting from a variety of causes such as poor oral hygiene, dental or oral infections, or the ingestion of certain foods. Annotation: ID#: D006209

Hallermann's Syndrome

Definition: An oculomandibulofacial syndrome principally characterized by dyscephaly (usually brachycephaly), parrot nose, mandibular hypoplasia, proportionate nanism, hypotrichosis, bilateral congenital cataracts, and microphthalmia. (Dorland, 27th ed) Annotation: a form of craniofacial dysostosis with other abnorm; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006210

Hallervorden-Spatz Syndrome

Definition: A rare autosomal recessive degenerative disorder which usually presents in late childhood or adolescence. Clinical manifestations include progressive MUSCLE SPASTICITY; hyperreflexia; MUSCLE RIGIDITY; DYSTONIA; DYSARTHRIA; and intellectual deterioration which progresses to severe dementia over several years. Pathologic examination reveals neuronal atrophy in the globus pallidus and iron deposition in blood vessels and perivascular spaces. (From Adams et al., Principles of Neurology, 6th ed, p972; Davis & Robertson, Textbook of Neuropathology, 2nd ed, pp972-929) Annotation: DF: HALLERVORDEN SPATZ DIS ID#: D006211

Hallux Limitus

Definition: A bony proliferation and articular degeneration of the first METATARSOPHALANGEAL JOINT that is characterized by pain and a progressive decrease in the dorsiflexion range of motion. Annotation: ID#: D020857

Hallux Rigidus

Definition: A condition caused by degenerative arthritis (see OSTEOARTHRITIS) of the METATARSOPHALANGEAL JOINT of the great toe and characterized by pain and limited dorsiflexion, but relatively unrestricted plantar flexion. Annotation: ID#: D020859

Hallux Valgus

Definition: Lateral displacement of the great toe, producing deformity of the first metatarsophalangeal joint with callous, bursa, or bunion formation over the bony prominence. Annotation: note category: lateral displacement of big toe ID#: D006215


Definition: A focal malformation resembling a neoplasm, composed of an overgrowth of mature cells and tissues that normally occur in the affected area. Annotation: non-neoplastic; coord IM with precoord organ/diseases term (IM) ID#: D006222

Hamartoma Syndrome, Multiple

Definition: A hereditary disease characterized by multiple ectodermal, mesodermal, and endodermal nevoid and neoplastic anomalies. Papules of the face and oral mucosa are the most characteristic lesion. Other changes occur in the skin, in the thyroid, the breast, the gastrointestinal system, and the nervous system. Annotation: do not use /blood supply /chem /second /secret /ultrastruct ID#: D006223

Hand Deformities

Definition: Alterations or deviations from normal shape or size which result in a disfigurement of the hand. Annotation: GEN or unspecified only; prefer specifics ID#: D006226

Hand Deformities, Acquired

Definition: Deformities of the hand, or a part of the hand, acquired after birth as the result of injury or disease. Annotation: deformity of bone, joint, muscle, etc. ID#: D006227

Hand Deformities, Congenital

Definition: Alterations or deviations from normal shape or size which result in a disfigurement of the hand occurring at or before birth. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006228

Hand Dermatoses

Definition: Annotation: GEN & as coord for specific skin diseases of the hand but not as coord for neoplasms on the hand (use neopl coords (IM) with HAND (IM)); consider synonym for dermatitis of hand & do not add DERMATITIS unless one of the specific DERMATITIS terms in MeSH ID#: D006229

Hand Injuries

Definition: General or unspecified injuries to the hand. Annotation: consider also METACARPUS /inj; FINGER INJURIES is also available ID#: D006230

Hand, Foot and Mouth Disease

Definition: A mild, highly infectious viral disease of children, characterized by vesicular lesions in the mouth and on the hands and feet. It is caused by coxsackieviruses A. Annotation: do not confuse with FOOT-AND-MOUTH DISEASE caused by a picornavirus; DF: HAND FOOT MOUTH DIS ID#: D006232

Hand-Schueller-Christian Syndrome

Definition: Disseminated, chronic form of Langerhans-cell histiocytosis. It may exhibit the classic triad of exophthalmos, diabetes insipidus, and bone destruction. Annotation: a form of Langerhans-cell histiocytosis ID#: D006231

Hantavirus Infections

Definition: Infections with viruses of the genus HANTAVIRUS. This is associated with at least four clinical syndromes: HEMORRHAGIC FEVER WITH RENAL SYNDROME caused by viruses of the Hantaan group; a milder form of HFRS caused by SEOUL VIRUS; nephropathia epidemica caused by PUUMALA VIRUS; and HANTAVIRUS PULMONARY SYNDROME caused by SIN NOMBRE VIRUS. Annotation: GEN or unspecified; prefer specifics ID#: D018778

Hantavirus Pulmonary Syndrome

Definition: Acute respiratory illness in humans caused by the Muerto Canyon virus whose primary rodent reservoir is the deer mouse Peromyscus maniculatus. First identified in the southwestern United States, this syndrome is characterized most commonly by fever, myalgias, headache, cough, and rapid respiratory failure. Annotation: causes resp failure; DF: HANTAVIRUS PULM SYNDROME ID#: D018804

Hartnup Disease

Definition: A disorder of amino acid transport characterized by the childhood (or rarely adult) onset of photosensitive dermatitis and intermittent neurologic symptoms. Ataxia, personality changes, migraine headaches, and photophobia may occur periodically. The disorder results from impaired sodium-dependent transport of neutral amino acids across the brush border membrane of the small intestine and renal tubular epithelium. (From Menkes, Textbook of Child Neurology, 5th ed, pp59-60) Annotation: ID#: D006250

Hay Fever

Definition: A seasonal variety of allergic rhinitis, marked by acute conjunctivitis with lacrimation and itching, regarded as an allergic condition triggered by specific allergens. Annotation: may be caused by grasses (POACEAE), various types of pollen, etc.; note X ref: do not confuse with RHINITIS, ALLERGIC, NONSEASONAL ID#: D006255

Head and Neck Neoplasms

Definition: Soft tissue tumors or cancer arising from the mucosal surfaces of the LIP; oral cavity; PHARYNX; LARYNX; and cervical esophagus. Other sites included are the NOSE and PARANASAL SINUSES; SALIVARY GLANDS; THYROID GLAND and PARATHYROID GLANDS; and MELANOMA and non-melanoma skin cancers of the head and neck. (from Holland et al., Cancer Medicine, 4th ed, p1651) Annotation: soft tissue neopls only; GEN: prefer FACIAL NEOPLASMS, & other specific organ/neopl terms pertinent to the soft tissues of the head & neck; coord IM with histol type of neopl if possible; DF: HEAD NEOPLASMS or HEAD NEOPL ID#: D006258

Head Injuries, Closed

Definition: Traumatic injuries to the cranium where the integrity of the skull is not compromised and no bone fragments or other objects penetrate the skull and dura mater. This frequently results in mechanical injury being transmitted to intracranial structures which may produce traumatic brain injuries, hemorrhage, or cranial nerve injury. (From Rowland, Merritt's Textbook of Neurology, 9th ed, p417) Annotation: usually GEN or unspecified; coord with BRAIN INJURIES, TRAUMATIC only if both are discussed ID#: D016489

Head Injuries, Penetrating

Definition: Head injuries which feature compromise of the skull and dura mater. These may result from gunshot wounds (WOUNDS, GUNSHOT), stab wounds (WOUNDS, STAB), and other forms of trauma. Annotation: ID#: D020197


Definition: Pain in the cranial region that may occur as an isolated and benign symptom or as a manifestation of a wide variety of conditions including SUBARACHNOID HEMORRHAGE; CRANIOCEREBRAL TRAUMA; CENTRAL NERVOUS SYSTEM INFECTIONS; INTRACRANIAL HYPERTENSION; and other disorders. In general, recurrent headaches that are not associated with a primary disease process are referred to as HEADACHE DISORDERS (e.g., MIGRAINE). Annotation: HEADACHE DISORDERS; MIGRAINE; VASCULAR HEADACHE; CLUSTER HEADACHE & TENSION HEADACHE are also available but do not diagnose: use word of text; /drug ther: consider also ANALGESICS /ther use ID#: D006261

Headache Disorders

Definition: Common conditions characterized by persistent or recurrent headaches (see HEADACHE). Headache syndrome classification systems may be based on etiology (e.g., VASCULAR HEADACHE, post-traumatic headaches, etc.), temporal pattern (e.g., CLUSTER HEADACHE, paroxysmal hemicrania, etc.), and precipitating factors (e.g., cough headache). Annotation: ID#: D020773

Hearing Disorders

Definition: Conditions that impair the transmission or perception of auditory impulses and information from the level of the ear to the temporal cortices, including the sensorineural pathways. Annotation: GEN & unspecified; consider also DEAFNESS (see note there) & HEARING LOSS, PARTIAL (see note there) & their indentions ID#: D006311

Hearing Loss, Bilateral

Definition: Partial hearing loss in both ears. Annotation: = "partial hearing loss in both ears": differentiate from DEAFNESS, total hearing loss in both ears ID#: D006312

Hearing Loss, Central

Definition: Hearing loss due to disease of the central nervous system auditory pathways, which originate in the cochlear nuclei of the pons and then ascend bilaterally to reach the inferior colliculi of the midbrain, medial geniculate bodies of the thalamus, and then the auditory cortices located in the temporal lobes. Bilateral lesions of the auditory pathways are usually required to cause central hearing loss. Cortical deafness refers to loss of hearing due to bilateral auditory cortex lesions. Unilateral brain stem lesions involving the cochlear nuclei may result in unilateral hearing loss. Annotation: coord IM with VESTIBULOCOCHLEAR NERVE DISEASES (IM) for hearing loss due to cochlear nerve dis ID#: D006313

Hearing Loss, Conductive

Definition: Hearing loss due to interference with the acoustic transmission of sound to the cochlea. The interference is in the outer or middle ear. Annotation: MIXED CONDUCTIVE-SENSORINEURAL HEARING LOSS see HEARING DISORDERS is available ID#: D006314

Hearing Loss, High-Frequency

Definition: Hearing loss in frequencies above 1000 hertz. Annotation: hearing loss above 1000 hertz range ID#: D006316

Hearing Loss, Noise-Induced

Definition: Hearing loss from exposure to noise. The loss is often in the frequency range 4000-6000 hertz. Annotation: does not = NOISE /adv eff: consider this an alternate ID#: D006317

Hearing Loss, Partial

Definition: A condition in which the sense of hearing, although defective, is functional with or without a hearing aid. The hearing loss may affect one or both ears. The normal hearing level for speech is approximately 40-70 decibels I.S.O. (International Organization for Standardization) or 30-60 db A.S.A. (American Standards Association). Annotation: "hard of hearing"; defective hearing in one or both ears: differentiate from HEARING LOSS, BILATERAL ("partial hearing loss in both ears") ID#: D006318

Hearing Loss, Sensorineural

Definition: Hearing loss resulting from damage to the sensory mechanism internal from the oval and round windows. Annotation: HEARING LOSS, MIXED CONDUCTIVE-SENSORINEURAL see HEARING DISORDERS is available ID#: D006319

Heart Aneurysm

Definition: An aneurysmal dilatation of a portion of the wall of the ventricle, usually the left, or, rarely, a saccular protrusion through it (false aneurysm of the heart). It is usually consequent to myocardial infarction but other causes such as bacterial endocarditis or trauma have been described. (Dorland, 28th ed) Annotation: of myocardium only: not for CORONARY ANEURYSM ID#: D006322

Heart Arrest

Definition: Cessation of the heart beat. Annotation: ID#: D006323

Heart Block

Definition: Impairment of conduction in heart excitation. It is often applied specifically to atrioventricular heart block. (Dorland, 27th ed) Annotation: a type of arrhythmia ID#: D006327

Heart Defects, Congenital

Definition: Imperfections or malformations of the heart, existing at birth. Annotation: GEN only; do not use as coord for specific term /abnorm; cyanotic defects probably go here but do not also index under CYANOSIS unless especially discussed ID#: D006330

Heart Diseases

Definition: Annotation: usually dis of function: differentiate from MYOCARDIAL DISEASES, dis of myocardial tissue (see note there); cyanotic heart dis is probably HEART DEFECTS, CONGENITAL & not CYANOSIS unless especially discussed; parasitic dis of the heart: coord PARASITIC DISEASES or specific parasitic dis (IM) with MYOCARDIAL DISEASES (IM), not HEART DISEASES; heart dis, unspecified or specific, with rheumatic fever is probably RHEUMATIC HEART DISEASE: see note there ID#: D006331

Heart Failure, Congestive

Definition: A complication of HEART DISEASES. Defective cardiac filling and/or impaired contraction and emptying, resulting in the heart's inability to pump a sufficient amount of blood to meet the needs of the body tissues or to be able to do so only with an elevated filling pressure. (from Braunwald, Heart Disease, 5th ed) Annotation: "scompenso di cuore" is "heart decompensation" in Italian; do not confuse with CARDIOMYOPATHY, CONGESTIVE; heart failure that is not congestive is CARDIAC OUTPUT, LOW ID#: D006333

Heart Injuries

Definition: General or unspecified injuries to the heart. Annotation: coord IM with specific part of heart /inj (NIM) ID#: D006335

Heart Murmurs

Definition: Abnormal heart sounds heard during auscultation caused by alterations in the flow of blood into a chamber, through a valve, or by a valve opening or closing abnormally. They are classified by the time of occurrence during the cardiac cycle, the duration, and the intensity of the sound on a scale of I to V. Annotation: do not confuse with HEART SOUNDS, a physiol concept; /etiol: coord with specific heart valve disease (IM) ID#: D006337

Heart Neoplasms

Definition: Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with specific site in heart (NIM) + histol type of neopl (IM) ID#: D006338

Heart Rupture

Definition: Laceration or tearing of the walls of the heart, of the interatrial or interventricular septum, of the papillary muscles or chordae tendineae, or of any of the valves of the heart. Rupture may be due to a variety of pathological entities, however, the majority are secondary to myocardial infarction (HEART RUPTURE, POST-INFARCTION). Annotation: rupt of any part of heart as result of heart pathol: do not confuse with HEART RUPTURE, TRAUMATIC see HEART INJURIES; coord IM with specific part (IM) if pertinent but VENTRICULAR SEPTAL RUPTURE is available; usually caused by myocard infarct ( = HEART RUPTURE, POST-INFARCTION) ID#: D006341

Heart Rupture, Post-Infarction

Definition: Rupture of the heart after myocardial infarction. Annotation: do not coord with MYOCARDIAL INFARCTION unless specifically discussed ID#: D006342

Heart Septal Defects

Definition: Defects in the cardiac septa, resulting in abnormal communications between the opposite chambers of the heart. Annotation: GEN or unspecified; prefer specifics; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006343

Heart Septal Defects, Atrial

Definition: Defects in the septum between the atria of the heart, due to failure of fusion between either the septum secundum or the septum primum and the endocardial cushions. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006344

Heart Septal Defects, Ventricular

Definition: Congenital defects in the septum between the cardiac ventricles, most often due to failure of the bulbar septum to completely close the interventricular foramen. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006345

Heart Valve Diseases

Definition: Diseases caused by or resulting in abnormal functioning of heart valves. Annotation: coord IM with specific valve (IM) ID#: D006349

Heart Valve Prolapse

Definition: Displacement of the valves of the heart. Annotation: GEN or unspecified: prefer specific valve prolapse ID#: D016127


Definition: Substernal pain or burning sensation, usually associated with regurgitation of gastric juice into the esophagus. Annotation: ID#: D006356

Heartwater Disease

Definition: A tick-borne septicemic disease of ruminants caused by Cowdria ruminantium. Annotation: an animal dis caused by Cowdria ruminantium of the family Rickettsiaceae; tick-borne dis; check tag ANIMAL ID#: D006357

Heat Exhaustion

Definition: An effect of excessive exposure to heat occurring commonly among workers in furnace rooms, foundries, etc., although it may occur from exposure to the sun's heat (SUNSTROKE). It is marked by subnormal temperature, with dizziness, headache, nausea, and sometimes delirium and/or collapse. It is distinguished from HEAT STROKE, in which the body temperature may be dangerously elevated. (Dorland, 27th ed) Annotation: subnormal body temp: do not confuse with HEAT STROKE where body temp is dangerously high; SUNSTROKE is also available ID#: D006359

Heat Stress Disorders

Definition: A group of conditions due to overexposure to or overexertion in excess environmental temperature. It includes heat cramps, which are non-emergent and treated by salt replacement; HEAT EXHAUSTION, which is more serious, treated with fluid and salt replacement; and HEAT STROKE, a condition most commonly affecting extremes of age, especially the elderly, accompanied by convulsions, delusions, or coma and treated with cooling the body and replacement of fluids and salts. (From Segen, Dictionary of Modern Medicine, 1992) Annotation: GEN or unspecified; prefer specifics; DF: HEAT STRESS DIS ID#: D018882

Heat Stroke

Definition: Overexposure to heat or overexertion most common in old age or infancy but especially in the elderly, accompanied by convulsions, delusions, or coma. It is treated by cooling the body and replacing fluids and salts. (From Segen, Dictionary of Modern Medicine, 1992, p282) Annotation: a heat stress disorder where body temp is dangerously high: differentiate from HEAT EXHAUSTION where body temp is subnormal; SUNSTROKE is also available ID#: D018883

Heavy Chain Disease

Definition: A disorder of immunoglobulin synthesis in which large quantities of abnormal heavy chains are excreted in the urine. The amino acid sequences of the N-(amino-) terminal regions of these chains are normal, but they have a deletion extending from part of the variable domain through the first domain of the constant region, so that they cannot form cross-links to the light chains. The defect arises through faulty coupling of the variable (V) and constant (C) region genes. Annotation: specify the immunoglobulin fragment coord NIM, as gamma chain dis = HEAVY CHAIN DISEASE (IM) + IMMUNOGLOBULINS, GAMMA-CHAIN (NIM); ALPHA-CHAIN DISEASE see IMMUNOPROLIFERATIVE SMALL INTESTINAL DISEASE is available ID#: D006362

Heavy Metal Poisoning, Nervous System

Definition: Conditions associated with damage or dysfunction of the nervous system caused by exposure to heavy metals, which may cause a variety of central, peripheral, or autonomic nervous system injuries. Annotation: GEN: prefer specifics ID#: D020260

Helicobacter Infections

Definition: Infections with organisms of the genus HELICOBACTER, particularly, in humans, HELICOBACTER PYLORI. The clinical manifestations are focused in the stomach, usually the gastric mucosa and antrum, and the upper duodenum. This infection plays a major role in the pathogenesis of type B gastritis and peptic ulcer disease. Annotation: gram-neg bact infect; check text for genus & species: Campylobacter pylori = HELICOBACTER PYLORI; Campylobacter pylori infect = HELICOBACTER INFECTIONS (IM) + HELICOBACTER PYLORI (IM) but Campylobacter jejuni infect = CAMPYLOBACTER INFECTIONS (IM) + CAMPYLOBACTER JEJUNI (IM); DF: HELICOBACTER INFECT ID#: D016481

HELLP Syndrome

Definition: Hemolysis-elevated liver enzymes-low platelet count syndrome. A pre-eclamptic or eclamptic disorder with the findings shown in the clinical description from which the acronym is created. Severe hypertension may be present. Abnormal SGOT and SGPT levels also appear. (Jablonski, 2d ed) Annotation: Hemolysis-Elevated Liver enzymes-Low Platelet count syndrome; DF: HELLP ID#: D017359


Definition: Infestation with parasitic worms of the helminth class. Annotation: parasitic worm infect; GEN; /drug ther: consider also ANTHELMINTICS ID#: D006373

Helminthiasis, Animal

Definition: Infestation of animals with parasitic worms of the helminth class. The infestation may be experimental or veterinary. Annotation: exper or vet; GEN or unspecified; prefer specifics; don't forget to check tag ANIMAL ID#: D006374


Definition: A benign tumor of the nervous system that may occur sporadically or in association with HIPPEL-LINDAU DISEASE. It accounts for approximately 2% of intracranial tumors, arising most frequently in the cerebellar hemispheres and vermis. Histologically, the tumors are composed of multiple capillary and sinusoidal channels lined with endothelial cells and clusters of lipid-laden pseudoxanthoma cells. Usually solitary, these tumors can be multiple and may also occur in the brain stem, spinal cord, retina, and supratentorial compartment. Cerebellar hemangioblastomas usually present in the third decade with INTRACRANIAL HYPERTENSION, and ataxia. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2071-2) Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with CEREBELLAR NEOPLASMS (IM) or other precoord brain/neopl term (IM) ID#: D018325


Definition: A neoplasm derived from blood vessels, characterized by numerous prominent endothelial cells that occur singly, in aggregates, and as the lining of congeries of vascular tubes or channels. Hemangioendotheliomas are relatively rare and are of intermediate malignancy (between benign hemangiomas and conventional angiosarcomas). They affect men and women about equally and rarely develop in childhood. (From Stedman, 25th ed; Holland et al., Cancer Medicine, 3d ed, p1866) Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM) ID#: D006390

Hemangioendothelioma, Epithelioid

Definition: A tumor of medium-to-large veins, composed of plump-to-spindled endothelial cells that bulge into vascular spaces in a tombstone-like fashion. These tumors are thought to have "borderline" aggression, where one-third develop local recurrences, but only rarely metastasize. It is unclear whether the epithelioid hemangioendothelioma is truly neoplastic or an exuberant tissue reaction, nor is it clear if this is equivalent to Kimura's disease (see ANGIOLYMPHOID HYPERPLASIA WITH EOSINOPHILIA). (Segen, Dictionary of Modern Medicine, 1992) Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM) ID#: D018323


Definition: An extremely common benign tumor, occurring most commonly in infancy and childhood, made up of newly formed blood vessels, and resulting from malformation of angioblastic tissue of fetal life. It can occur anywhere in the body but is most frequently noticed in the skin and subcutaneous tissues. About 75% are present at birth, and about 60% occur in the head and neck area. The majority in infancy will regress spontaneously. Some hemangiomas grow rapidly during the early months of life and may be a source of some concern, although virtually all disappear by about 5 years of age. They do not metastasize and simple excision will often be curative. (Dorland, 27th ed; from Stedman, 25th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1355) Annotation: coord IM with precoord organ/neopl term (IM); CENTRAL NERVOUS SYSTEM VENOUS ANGIOMA is also available ID#: D006391

Hemangioma, Capillary

Definition: A dull red, firm, dome-shaped hemangioma, sharply demarcated from surrounding skin, usually located on the head and neck, which grows rapidly and generally undergoes regression and involution without scarring. It is caused by proliferation of immature capillary vessels in active stroma, and is usually present at birth or occurs within the first two or three months of life. (Dorland, 27th ed) Annotation: coord IM with precoord organ/neopl term (IM); do not confuse with HEMANGIOMA, LOBULAR CAPILLARY see GRANULOMA, PYOGENIC; distinguish from PORT-WINE STAIN ID#: D018324

Hemangioma, Cavernous

Definition: A vascular tumor preponderantly composed of large dilated blood vessels, often containing large amounts of blood, occurring in the skin, subcutaneously, or both, and also in many viscera, particularly the liver, spleen, pancreas, and sometimes the brain. The typical superficial lesions are bright to dark red in color; deep lesions have a blue color. A cavernous hemangioma in the skin extends more deeply than a capillary hemangioma and is less likely to regress spontaneously. (Dorland, 27th ed; from Stedman, 25th ed) Annotation: /blood supply /chem /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM) ID#: D006392

Hemangioma, Cavernous, Central Nervous System

Definition: A vascular malformation composed of clusters of large, thin walled veins lacking intervening nervous tissue. They are most common in the BRAIN STEM but may also occur in the cerebral hemispheres, diencephalon, cerebellum, and spinal cord. The lesions have a tendency to rupture and cause a variety of clinical deficits (e.g., SEIZURES; hemiparesis) that depend upon the location of the hemorrhage. (From Adams et al., Principles of Neurology, 6th ed, pp851-2) Annotation: coord (IM) with CENTRAL NERVOUS SYSTEM NEOPLASMS or specific (IM) ID#: D020786


Definition: A tumor composed of spindle cells with a rich vascular network, which apparently arises from pericytes, cells of smooth muscle origin that lie around small vessels. Benign and malignant hemangiopericytomas exist, and the rarity of these lesions has led to considerable confusion in distinguishing between benign and malignant variants. (From Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1364) Annotation: benign or malignant; /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM) ID#: D006393


Definition: A rare malignant neoplasm characterized by rapidly proliferating, extensively infiltrating, anaplastic cells derived from blood vessels and lining irregular blood-filled or lumpy spaces. (Stedman, 25th ed) Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM) ID#: D006394


Definition: Bleeding into the joints. It may arise from trauma or spontaneously in patients with hemophilia. Annotation: ID#: D006395


Definition: Vomiting of blood. Annotation: ID#: D006396


Definition: Hemorrhage into a canal or cavity of the body, especially into the tunica vaginalis testis. Annotation: ID#: D006398


Definition: An accumulation of menstrual blood in the vagina. (Dorland, 28th ed) Annotation: "accumulation of menstrual blood in the vagina" ID#: D006399

Hematologic Diseases

Definition: Disorders of the blood and blood forming tissues. Annotation: GEN or unspecified: prefer specifics; DF: HEMATOL DIS ID#: D006402

Hematologic Neoplasms

Definition: Neoplasms located in the blood and blood-forming tissue (the bone marrow and lymphatic tissue). The commonest forms are the various types of LEUKEMIA, of LYMPHOMA, and of the progressive, life-threatening forms of the MYELODYSPLASTIC SYNDROMES. Annotation: GEN or unspecified only; prefer LEUKEMIA or LYMPHOMA or their specifics; do not use /blood supply /second /secret; DF: HEMATOL NEOPL ID#: D019337


Definition: An extravasation of blood localized in an organ, space, or tissue. Annotation: IM; not a neoplasm: coord with organ /dis or organ /hemorrhage term (IM) ID#: D006406

Hematoma, Epidural

Definition: Accumulation of blood in the cranial epidural space due to rupture of the middle meningeal artery or rarely the meningeal vein, often associated with a temporal or parietal bone fracture. The hematoma tends to expand rapidly, compressing the dura and underlying brain. Clinical features include the acute or subacute onset of headache, VOMITING, alterations of mentation, and hemiparesis (see HEMIPLEGIA). The natural history of the process is progression to coma and eventually death. (Adams et al., Principles of Neurology, 6th ed, p885) Annotation: ID#: D006407

Hematoma, Subdural

Definition: Extravasation and subsequent accumulation of blood in the subdural space between the dural and arachnoidal layers of the meninges. This condition primarily occurs over the surface of a cerebral hemisphere, but may develop in the posterior fossa and spinal canal. Acute (HEMATOMA, SUBDURAL, ACUTE) and chronic (HEMATOMA, SUBDURAL, CHRONIC) forms exist. Annotation: ID#: D006408

Hematoma, Subdural, Acute

Definition: Hemorrhage and accumulation of blood in the subdural space associated with the acute onset of neurologic deficits, usually following CRANIOCEREBRAL TRAUMA. Hematoma formation occurs most frequently over the lateral and superior aspects of a cerebral hemisphere, but may also occur in the posterior fossa and spinal canal. Clinical manifestations may include hemiparesis, SEIZURES, third nerve palsy (see OCULOMOTOR NERVE DISEASES), mental status changes, and COMA. (From Adams et al., Principles of Neurology, 6th ed, p886) Annotation: ID#: D020199

Hematoma, Subdural, Chronic

Definition: Chronic accumulation of blood in the subdural space, most frequently occurring over the lateral and superior aspects of a cerebral hemisphere. Clinical manifestations may be delayed for days to weeks, when affected individuals may present with confusion, drowsiness, hemiparesis, ATAXIA, APHASIA, and other signs of neurologic dysfunction. The condition tends to occur after the age of 50 years. It may be spontaneous, follow CRANIOCEREBRAL TRAUMA, or occur in association with bleeding disorders, the use of anticoagulant medication, locally invasive tumors, and other disorders. (From Adams et al., Principles of Neurology, 6th ed, p887) Annotation: ID#: D020200


Definition: An accumulation of blood in the uterus. (Dorland, 28th ed) Annotation: "accumulation of blood in the uterus"; do not confuse with UTERINE HEMORRHAGE ID#: D006409


Definition: Presence of blood in the urine. Annotation: ID#: D006417


Definition: Partial or complete loss of vision in one half of the visual field(s) of one or both eyes. Subtypes include altitudinal hemianopsia, characterized by a visual defect above or below the horizontal meridian of the visual field. Homonymous hemianopsia refers to a visual defect that affects both eyes equally, and occurs either to the left or right of the midline of the visual field. Binasal hemianopsia consists of loss of vision in the nasal hemifields of both eyes. Bitemporal hemianopsia is the bilateral loss of vision in the temporal fields. Quadrantanopsia refers to loss of vision in one quarter of the visual field in one or both eyes. Annotation: ID#: D006423

Hemic and Lymphatic Diseases

Definition: Hematologic diseases and diseases of the lymphatic system collectively. Hemic diseases include disorders involving the formed elements (e.g., ERYTHROCYTE AGGREGATION, INTRAVASCULAR) and chemical components (e.g., BLOOD PROTEIN DISORDERS); lymphatic diseases include disorders relating to lymph, lymph nodes, and lymphocytes. Annotation: avoid: too general; prefer HEMATOLOGIC DISEASES & its specifics or LYMPHATIC DISEASES & its specifics; DF: HEMIC LYMPHATIC DIS CATALOG: do not use ID#: D006425

Hemifacial Spasm

Definition: Recurrent clonic contraction of facial muscles, restricted to one side. It may occur as a manifestation of compressive lesions involving the seventh cranial nerve (FACIAL NERVE DISEASES), during recovery from BELL PALSY, or in association with other disorders. (From Adams et al., Principles of Neurology, 6th ed, p1378) Annotation: ID#: D019569


Definition: Severe or complete loss of motor function on one side of the body. This condition is usually caused by BRAIN DISEASES that are localized to the cerebral hemisphere opposite to the side of weakness. Less frequently, BRAIN STEM lesions; cervical SPINAL CORD DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; and other conditions may manifest as hemiplegia. The term hemiparesis (see PARESIS) refers to mild to moderate weakness involving one side of the body. Annotation: ID#: D006429


Definition: Hemorrhage in or through the biliary tract, due to trauma, inflammation, cholelithiasis, vascular disease, or neoplasms. Annotation: ID#: D006431


Definition: A disorder due to the deposition of hemosiderin in the parenchymal cells, causing tissue damage and dysfunction of the liver, pancreas, heart, and pituitary. Full development of the disease in women is restricted by menstruation, pregnancy, and lower dietary intake of iron. Acquired hemochromatosis may be the result of blood transfusions, excessive dietary iron, or secondary to other disease. Idiopathic or genetic hemochromatosis is an autosomal recessive disorder of metabolism associated with a gene tightly linked to the A locus of the HLA complex on chromosome 6. (From Dorland, 27th ed) Annotation: accumulation of hemosiderin in tissue ID#: D006432

Hemoglobin C Disease

Definition: A disease characterized by compensated hemolysis with a normal hemoglobin level or a mild to moderate anemia. There may be intermittent abdominal discomfort, splenomegaly, and slight jaundice. Annotation: a congen hemolytic anemia; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; do not confuse with HEMOGLOBIN SC DISEASE ID#: D006445

Hemoglobin SC Disease

Definition: One of the sickle cell disorders characterized by the presence of both hemoglobin S and hemoglobin C. It is similar to, but less severe than sickle cell anemia. Annotation: a sickle cell anemia; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; do not confuse with HEMOGLOBIN C DISEASE ID#: D006450


Definition: A group of inherited disorders characterized by structural alterations within the hemoglobin molecule. Annotation: do not confuse with HEMOGLOBINS, ABNORMAL (D12): use term in the text; coord IM with specific abnormal hemoglobin (IM) but HEMOGLOBIN C DISEASE; THALASSEMIA (hemoglobin H disease) & ANEMIA, SICKLE CELL (hemoglobin S disease) are available ID#: D006453


Definition: The presence of free hemoglobin in the urine. Annotation: HEMOGLOBINURIA, PAROXYSMAL is also available: see note there ID#: D006456

Hemoglobinuria, Paroxysmal

Definition: Disorder characterized by intravascular hemolysis and hemoglobinuria. Some cases occur on exposure to cold and are due to the presence of an autohemolysin in the serum. Other cases are more marked during or immediately after sleep and are considered to be due to an acquired intracorpuscular defect. Annotation: also called "paroxysmal nocturnal hemoglobinuria" so ignore "nocturnal" ID#: D006457

Hemolytic-Uremic Syndrome

Definition: Syndrome of hemolytic anemia, thrombocytopenia, and acute renal failure, with pathological finding of thrombotic microangiopathy in kidney and renal cortical necrosis. Annotation: ID#: D006463


Definition: Hemorrhage into the peritoneal cavity. Annotation: ID#: D006465

Hemophilia A

Definition: The classic hemophilia resulting from a deficiency of factor VIII. It is an inherited disorder of blood coagulation characterized by a permanent tendency to hemorrhage. Annotation: do not coord with INFANT, NEWBORN, DISEASES ID#: D006467

Hemophilia B

Definition: A deficiency of blood coagulation factor IX inherited as an X-linked disorder. (Also known as Christmas Disease, after the first patient studied in detail, not the holy day.) Historical and clinical features resemble those in classic hemophilia (HEMOPHILIA A), but patients present with fewer symptoms. Severity of bleeding is usually similar in members of a single family. Many patients are asymptomatic until the hemostatic system is stressed by surgery or trauma. Treatment is similar to that for hemophilia A. (From Cecil Textbook of Medicine, 19th ed, p1008) Annotation: ID#: D002836


Definition: Collection of air and blood in the pleural cavity. Annotation: ID#: D006468


Definition: Bronchial hemorrhage manifested with spitting of blood. Annotation: ID#: D006469


Definition: Bleeding or escape of blood from a vessel. Annotation: GEN or unspecified; prefer specifics; coord IM with organ/dis precoord (IM), not organ /blood supply; consider also terms for presence of blood within cavities, as HEMOTHORAX; HEMATOCOLPOS; etc. ID#: D006470

Hemorrhagic Bacteremia

Definition: Any of several diseases usually caused by PASTEURELLA MULTOCIDA, marked by the presence of hemorrhagic areas in the subcutaneous tissues, serous membranes, muscles, lymph glands, and throughout the internal organs. Annotation: caused by Pasteurella multocida infect ID#: D006483

Hemorrhagic Disease of Newborn

Definition: A self-limited hemorrhagic disorder of the first days of life, caused by a deficiency of the vitamin K-dependent blood coagulation factors II, VII, IX, and X. (Dorland, 27th ed) Annotation: do not confuse with HEMOLYTIC DISEASE OF NEWBORN see ERYTHROBLASTOSIS, FETAL; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006475

Hemorrhagic Disorders

Definition: Spontaneous or near spontaneous bleeding caused by a defect in clotting mechanisms (BLOOD COAGULATION DISORDERS) or another abnormality causing a structural flaw in the blood vessels (VASCULAR HEMOSTATIC DISORDERS). Annotation: "predisposition to abnormal hemostasis"; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006474

Hemorrhagic Fever with Renal Syndrome

Definition: An acute febrile disease occurring predominately in Asia. It is characterized by fever, prostration, vomiting, hemorrhagic phenonema, shock, and renal failure. It is caused by any one of several closely related species of the genus Hantavirus. The most severe form is caused by HANTAAN VIRUS whose natural host is the rodent Apodemus agrarius. Milder forms are caused by SEOUL VIRUS and transmitted by the rodents Rattus rattus and R. norvegicus, and the PUUMALA VIRUS with transmission by Clethrionomys galreolus. Annotation: ID#: D006480

Hemorrhagic Fever, American

Definition: Diseases caused by American hemorrhagic fever viruses (ARENAVIRUSES, NEW WORLD). Annotation: caused by ARENAVIRUSES, NEW WORLD ID#: D006478

Hemorrhagic Fever, Crimean

Definition: A severe, often fatal disease in humans caused by the Crimean-Congo hemorrhagic fever virus (HEMORRHAGIC FEVER VIRUS, CRIMEAN-CONGO). Annotation: caused by the Crimean-Congo hemorrhagic fever virus, a species of Nairovirus ID#: D006479

Hemorrhagic Fever, Ebola

Definition: A highly fatal, acute hemorrhagic fever, clinically very similar to MARBURG VIRUS DISEASE, caused by the EBOLA VIRUS, first occurring in the Sudan and adjacent northwestern (what was then) Zaire. The natural reservoir and mode of transmission of the virus are unknown, but secondary infection is by direct contact with infected blood and other body secretions. (From Dorland, 28th ed) Annotation: caused by Ebola virus, a species of Filovirus ID#: D019142

Hemorrhagic Fever, Omsk

Definition: Infection with the Omsk hemorrhagic fever virus, a Flavivirus. Annotation: caused by a flavivirus ID#: D006481

Hemorrhagic Fevers, Viral

Definition: A group of viral diseases of diverse etiology but having many similar clinical characteristics; increased capillary permeability, leukopenia, and thrombocytopenia are common to all. Hemorrhagic fevers are characterized by sudden onset, fever, headache, generalized myalgia, backache, conjunctivitis, and severe prostration, followed by various hemorrhagic symptoms. Hemorrhagic fever with kidney involvement is HEMORRHAGIC FEVER WITH RENAL SYNDROME. Annotation: GEN or unspecified; prefer specifics; if renal involvement, dis is probably HEMORRHAGIC FEVER WITH RENAL SYNDROME ID#: D006482

Hemorrhagic Syndrome, Bovine

Definition: Clinically severe acute disease of cattle caused by noncytopathic forms of Bovine viral diarrhea virus 2 (DIARRHEA VIRUS 2, BOVINE VIRAL). Outbreaks are characterized by high morbidity and high mortality. Annotation: ID#: D030243


Definition: Varicosities of the hemorrhoidal venous plexuses. Annotation: ID#: D006484


Definition: Conditions in which there is a generalized increase in the iron stores of body tissues, particularly of liver and the reticuloendothelial system, without demonstrable tissue damage. The name refers to the presence of stainable iron in the tissue in the form of hemosiderin. Annotation: a form of tissue iron accumulation in total body iron overload ID#: D006486


Definition: Hemorrhage within the pleural cavity. Annotation: ID#: D006491

Hepadnaviridae Infections

Definition: Virus diseases caused by the HEPADNAVIRIDAE. Annotation: GEN or unspecified; prefer specific ID#: D018347

Hepatic Encephalopathy

Definition: A syndrome characterized by central nervous system dysfunction in association with LIVER FAILURE, including portal-systemic shunts. Clinical features include lethargy and CONFUSION (frequently progressing to COMA); asterixis; NYSTAGMUS; brisk oculovestibular reflexes; decorticate and decerebrate posturing; MUSCLE SPASTICITY; and bilateral extensor plantar reflexes (see REFLEX, BABINSKI). ELECTROENCEPHALOGRAPHY may demonstrate triphasic waves. (From Adams et al., Principles of Neurology, 6th ed, pp1117-20; Plum & Posner, Diagnosis of Stupor and Coma, 3rd ed, p222-5) Annotation: ID#: D006501

Hepatic Vein Thrombosis

Definition: Occlusion of the hepatic veins caused by thrombi or fibrous obliteration of the veins. Annotation: do not confuse X ref CHIARI'S SYNDROME with ARNOLD-CHIARI SYNDROME see ARNOLD-CHIARI MALFORMATION ID#: D006502

Hepatic Veno-Occlusive Disease

Definition: Blockage of the small- or medium-sized hepatic veins due to nonthrombotic subendothelial edema which may progress to fibrosis. Annotation: hepatic vein blockage; DF: HVOD ID#: D006504


Definition: Inflammation of the liver and liver disease involving degenerative or necrotic alterations of hepatocytes. Annotation: GEN or unspecified; prefer specifics; probably non-viral; viral hepatitis = HEPATITIS, VIRAL, HUMAN & HEPATITIS, VIRAL, ANIMAL or their specifics; /chem ind = HEPATITIS, TOXIC but note HEPATITIS, ALCOHOLIC is also available; /vet = HEPATITIS, ANIMAL or HEPATITIS, VIRAL, ANIMAL; hepatitis A, hepatitis B, etc. = HEPATITIS A; HEPATITIS B; etc.; hepatitis parenterally transmitted = HEPATITIS C, enterally transmitted = HEPATITIS E, not specified as parenteral or enteral = probably HEPATITIS, VIRAL, HUMAN; non-A, non-B hepatitis = probably HEPATITIS C but check text for mode of transmission; "transmission of hepatitis" is probably /transm with one of the viral hepatitis terms ID#: D006505

Hepatitis A

Definition: Hepatitis caused by HEPATOVIRUS. It can be transmitted through fecal contamination of food or water. Annotation: caused by a human hepatitis virus ID#: D006506

Hepatitis B

Definition: Hepatitis caused by hepatitis B virus. It may be transmitted by transfusion of contaminated blood or blood products. Annotation: caused by a human hepatitis virus; chronic = HEPATITIS B, CHRONIC ID#: D006509

Hepatitis B, Chronic

Definition: An inflammatory disease of the liver caused by hepatitis B virus and lasting six months or more. Annotation: ID#: D019694

Hepatitis C

Definition: A form of hepatitis, similar to type B post-transfusion hepatitis, but caused by a virus which is serologically distinct from the agents of hepatitis A, B, and E, and which may persist in the blood of chronic asymptomatic carriers. Hepatitis C is parenterally transmitted and associated with transfusions and drug abuse. Annotation: caused by a member of the family Flaviviridae; parenterally transmitted: hepatitis not specified as enteral or parenteral is indexed under HEPATITIS, VIRAL, HUMAN; chronic = HEPATITIS C, CHRONIC ID#: D006526

Hepatitis C, Chronic

Definition: An inflammatory disease of the liver caused by hepatitis C virus lasting six months or more. Annotation: ID#: D019698

Hepatitis D

Definition: Hepatitis caused by the HEPATITIS DELTA VIRUS in association with hepatitis B. It is endemic in some European countries and is seen in drug users, hemophiliacs, and polytransfused persons. Annotation: a hepatitis caused by hepatitis delta virus; HEPATITIS D, CHRONIC is also available ID#: D003699

Hepatitis D, Chronic

Definition: Inflammatory disease of the liver caused by hepatitis D virus in conjunction with hepatitis B virus and lasting six months or more. Annotation: ID#: D019701

Hepatitis E

Definition: An acute form of hepatitis caused by a virus serologically distinct from the agents of hepatitis A, B, and C. Hepatitis E is associated with fecally-contaminated water, is enterically transmitted, and is commonly found in tropical or subtropical countries. Annotation: enterally transmitted: hepatitis not specified as enteral or parenteral is indexed under HEPATITIS, VIRAL, HUMAN ID#: D016751

Hepatitis, Alcoholic

Definition: An acute or chronic degenerative and inflammatory lesion of the liver in the alcoholic which is potentially progressive though sometimes reversible. It does not necessarily include steatosis, fibrosis, or cirrhosis of alcoholics, although it is frequently associated with these conditions. It is characterized by liver cell necrosis, infiltration by polymorphonuclear leukocytes and lymphocytes, and Mallory bodies. The morphologic changes of chronic alcoholic hepatitis are not likely to be confused with chronic hepatitis (HEPATITIS, CHRONIC). Annotation: considered chronic so do not coord with CHRONIC DISEASE ID#: D006519

Hepatitis, Animal

Definition: Annotation: exper or vet, GEN or unspecified; don't forget to check tag ANIMAL; prefer specific hepatitis heading with check tag ANIMAL & do not coord here: if specific hepatitis is exper, use only check tag ANIMAL but if specific hepatitis is vet, use specific hepatitis /vet (IM) + precoord animal/dis term (IM) + check tag ANIMAL ID#: D006520

Hepatitis, Autoimmune

Definition: An unresolving, predominately periportal, hepatitis, usually with hypergammaglobulinemia and serum autoantibodies. The existence of subgroups (types 1, 2, and 3) based on serological findings are controversial. Additionally, some patients have variant forms, where there are features associated with both autoimmune hepatitis and another type of chronic liver disease (overlap syndromes) or where there are findings incompatible with autoimmune hepatitis (outlier syndromes). (From Czaja, Ann Intern Med. 1996; 125:588-598) Annotation: a form of chronic hepatitis ID#: D019693

Hepatitis, Chronic

Definition: A collective term for a clinical and pathological syndrome which has several causes and is characterized by varying degrees of hepatocellular necrosis and inflammation. Specific forms of chronic hepatitis include autoimmune hepatitis (HEPATITIS, AUTOIMMUNE), chronic hepatitis B; (HEPATITIS B, CHRONIC), chronic hepatitis C; (HEPATITIS C, CHRONIC), chronic hepatitis D; (HEPATITIS D, CHRONIC), indeterminate chronic viral hepatitis, cryptogenic chronic hepatitis and drug-related chronic hepatitis (HEPATITIS, CHRONIC, DRUG-INDUCED). Annotation: chronic hepatitis from any cause; GEN or unspecified; prefer specifics; chronic alcoholic hepatitis = HEPATITIS, ALCOHOLIC ID#: D006521

Hepatitis, Chronic, Drug-Induced

Definition: An inflammatory disease of the liver, lasting six months or more, and caused by an adverse drug effect. The adverse effect may result from a direct toxic effect of a drug or metabolite, or an idiosyncratic response to a drug or metabolite. The clinical and histological changes can mimic viral or autoimmune hepatitis. Annotation: coord IM with specific toxic agent /adv eff-pois-tox (IM); HEPATITIS, ALCOHOLIC is also available ID#: D019702

Hepatitis, Infectious Canine

Definition: An adenovirus infection causing fever, edema, vomiting, and diarrhea in dogs, especially puppies. In foxes it causes acute encephalitis with convulsions, paralysis, coma, and death. Annotation: caused by an adenovirus; don't forget also DOGS (NIM) & check tag ANIMAL; DF: HEPATITIS INFECT CANINE ID#: D006522

Hepatitis, Toxic

Definition: Acute hepatitis caused by true hepatotoxins such as Amanita phaloides toxin, carbon tetrachloride, yellow phosphorus, and a variety of drugs. (From Dorland, 28th ed) Annotation: coord IM with specific toxic agent /adv eff-pois-tox (IM); chronic = HEPATITIS, CHRONIC, DRUG-INDUCED; HEPATITIS, ALCOHOLIC is also available ID#: D006523

Hepatitis, Viral, Animal

Definition: Viral hepatitis in animals. Annotation: not restricted to hepatitis caused by hepatitis viruses: use also for hepatitis caused by other viruses; exper or vet but do not use /vet; don't forget to check tag ANIMAL ID#: D006524

Hepatitis, Viral, Human

Definition: Viral hepatitis in man. Annotation: not restricted to hepatitis caused by hepatitis viruses: use also for hepatitis caused by other viruses; coord IM with precoord virus dis term (IM); parenterally transmitted hepatitis = HEPATITIS C, enterically transmitted hepatitis = HEPATITIS E, not specified as enteral or parenteral = HEPATITIS, VIRAL, HUMAN; HEPATITIS A; HEPATITIS B & HEPATITIS D are also available ID#: D006525


Definition: A malignant neoplasm occurring in young children, primarily in the liver, composed of tissue resembling embryonal or fetal hepatic epithelium, or mixed epithelial and mesenchymal tissues. (Stedman, 25th ed) Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with LIVER NEOPLASMS (IM) ID#: D018197

Hepatolenticular Degeneration

Definition: A rare autosomal recessive disease characterized by the deposition of copper in the BRAIN; LIVER; CORNEA; and other organs. Clinical features include LIVER CIRRHOSIS; LIVER FAILURE; SPLENOMEGALY; TREMOR; bradykinesia; DYSARTHRIA; CHOREA; MUSCLE RIGIDITY; Kayser-Fleischer rings (pigmented corneal lesions); ATAXIA; and intellectual deterioration. Hepatic dysfunction may precede neurologic dysfunction by several years. (From Adams et al., Principles of Neurology, 6th ed pp969-71) Annotation: lenticular refers to the lenticular nucleus in the brain ID#: D006527


Definition: Enlargement of the liver. Annotation: NIM when symptom ID#: D006529

Hepatopulmonary Syndrome

Definition: A syndrome consisting of the triad of liver dysfunction, pulmonary vascular dilatation, and abnormal arterial oxygenation in the absence of detectable intrinsic disease of the lung and heart. Annotation: ID#: D020065

Hepatorenal Syndrome

Definition: Renal failure in those with liver disease, usually liver cirrhosis or obstructive jaundice. Historically called Heyd disease, urohepatic syndrome, or bile nephrosis. Annotation: kidney failure in liver dis ID#: D006530

Hereditary Central Nervous System Demyelinating Diseases

Definition: Inherited conditions characterized by a loss of myelin in the central nervous system. Annotation: ID#: D020279

Hereditary Motor and Sensory Neuropathies

Definition: A group of slowly progressive inherited disorders affecting motor and sensory peripheral nerves. Subtypes include HMSNs I-VII. HMSN I and II both refer to CHARCOT-MARIE-TOOTH DISEASE. HMSN III refers to hypertrophic neuropathy of infancy, HMSN IV refers to REFSUM DISEASE, HMSN V refers to a condition marked by a hereditary motor and sensory neuropathy associated with spastic paraplegia (see SPASTIC PARAPLEGIA, HEREDITARY). HMSN VI refers to HMSN associated with an inherited optic atrophy (OPTIC ATROPHIES, HEREDITARY), and HMSN VII refers to HMSN associated with retinitis pigmentosa. (From Adams et al., Principles of Neurology, 6th ed, p1343) Annotation: do not confuse with HEREDITARY MOTOR AND AUTONOMIC NEUROPATHIES; DF: NEUROPATHIES HEREDITARY MOTOR SENSORY ID#: D015417

Hereditary Sensory and Autonomic Neuropathies

Definition: A group of inherited disorders characterized by degeneration of dorsal root and autonomic ganglion cells, and clinically by loss of sensation and autonomic dysfunction. There are five subtypes. Type I features autosomal dominant inheritance and distal sensory involvement. Type II is characterized by autosomal inheritance and distal and proximal sensory loss. Type III is DYSAUTONOMIA, FAMILIAL. Type IV features insensitivity to pain, heat intolerance, and mental deficiency. Type V is characterized by a selective loss of pain with intact light touch and vibratory sensation. (From Joynt, Clinical Neurology, 1995, Ch51, pp142-4) Annotation: do not confuse with HEREDITARY MOTOR AND SENSORY NEUROPATHIES; for X refs to HSAN types: HSAN TYPE III is see DYSAUTONOMIA, FAMILIAL ID#: D009477

Heredodegenerative Disorders, Nervous System

Definition: Inherited disorders characterized by progressive atrophy and dysfunction of anatomically or physiologically related neurologic systems. Annotation: ID#: D020271

Hermanski-Pudlak Syndrome

Definition: Syndrome characterized by the triad of oculocutaneous albinism (ALBINISM, OCULOCUTANEOUS); PLATELET STORAGE POOL DEFICIENCY; and lysosomal accumulation of ceroid lipofuscin. Annotation: ID#: D022861


Definition: Originally, a state characterized by the presence of both male and female sex organs. In humans, true hermaphroditism is caused by anomalous differentiation of the gonads, with the presence of both ovarian and testicular tissue and of ambiguous morphologic criteria of sex. If only testicular tissue is present, but there are some female morphological criteria of sex, it is known as male PSEUDOHERMAPHRODITISM. If only ovarian tissue is present, but there are some male morphological criteria of sex, it is known as female PSEUDOHERMAPHRODITISM. (Dorland, 27th ed) Annotation: permissible for biol hermaphroditism in lower organisms despite category; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; for check tag use genetic sex for higher animals but do not check sex tags for lower organisms; do not confuse with BISEXUALITY, a behavioral term ID#: D006546


Definition: Protrusion of a loop or knuckle of an organ or tissue through an abnormal opening. Annotation: GEN or unspecified; prefer specifics; NIM coord with specific organ/dis (IM) ID#: D006547

Hernia, Diaphragmatic

Definition: Protrusion of some part of the abdominal or retroperitoneal structures through the diaphragm into the thorax. (Dorland, 27th ed) Annotation: ID#: D006548

Hernia, Diaphragmatic, Traumatic

Definition: Protrusion of some part of the abdominal or retroperitoneal structures through the diaphragm into the thorax, occurring as a result of injury, usually to the abdomen. (From Dorland, 27th ed) Annotation: ID#: D006549

Hernia, Femoral

Definition: Annotation: ID#: D006550

Hernia, Hiatal

Definition: Herniation of the lower esophagus and/or portion of the stomach through the esophageal hiatus. Annotation: herniation through diaphragmatic opening; don't specify esophagus or stomach ID#: D006551

Hernia, Inguinal

Definition: Annotation: ID#: D006552

Hernia, Obturator

Definition: Hernia through the obturator foramen. Annotation: ID#: D006553

Hernia, Umbilical

Definition: The protrusion of part of the intestine at the umbilicus (Dorland, 27th ed). Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006554

Hernia, Ventral

Definition: Annotation: ID#: D006555


Definition: Annotation: caused by Coxsackie A virus ID#: D006557

Herpes Genitalis

Definition: Herpes simplex of the genitals. Annotation: ID#: D006558

Herpes Gestationis

Definition: An itching polymorphous bullous eruption which occurs in pregnancy or the puerperium and which recurs in successive pregnancies. Annotation: not caused by Herpesvirus: herpes refers here to the polymorphous eruptions; don't forget check tags PREGNANCY + FEMALE ID#: D006559

Herpes Labialis

Definition: Herpes simplex, caused by type 1 virus, primarily spread by oral secretions and usually occurring as a concomitant of fever. It may also develop in the absence of fever or prior illness. It commonly involves the facial region, especially the lips and the nares. (Dorland, 27th ed.) Annotation: herpes simplex of the lips & nares; STOMATITIS, HERPETIC (oral cavity) is also available ID#: D006560

Herpes Simplex

Definition: A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. (Dorland, 27th ed.) Annotation: note Cat C; caused by Simplexvirus (also called Herpes simplex virus & Herpesvirus hominis) ID#: D006561

Herpes Zoster

Definition: An acute infectious, usually self-limited, disease believed to represent activation of latent varicella-zoster virus (HERPESVIRUS 3, HUMAN) in those who have been rendered partially immune after a previous attack of chickenpox. It involves the sensory ganglia and their areas of innervation and is characterized by severe neuralgic pain along the distribution of the affected nerve and crops of clustered vesicles over the area. (From Dorland, 27th ed) Annotation: caused by human herpesvirus 3 (HERPES ZOSTER VIRUS see HERPESVIRUS 3, HUMAN) ID#: D006562

Herpes Zoster Ophthalmicus

Definition: Virus infection of the Gasserian ganglion and its nerve branches characterized by pain and vesicular eruptions with much swelling. Ocular involvement is usually heralded by a vesicle on the tip of the nose. This area is innervated by the nasociliary nerve. Annotation: caused by human herpesvirus 3 (OCULAR HERPES ZOSTER VIRUS see HERPESVIRUS 3, HUMAN) ID#: D006563

Herpes Zoster Oticus

Definition: A syndrome characterized by facial palsy in association with a herpetic eruption of the external auditory meatus. This may occasionally be associated with tinnitus, vertigo, deafness, severe otalgia, and inflammation of the pinna. The condition is caused by reactivation of a latent HERPESVIRUS 3, HUMAN infection which causes inflammation of the facial and vestibular nerves, and may occasionally involve additional cranial nerves. (From Adams et al., Principles of Neurology, 6th ed, p757) Annotation: do not confuse X ref RAMSAY HUNT AURICULAR SYNDROME with RAMSAY HUNT PARALYSIS SYNDROME see PARKINSONIAN DISORDERS or RAMSAY HUNT CEREBELLAR SYNDROME see MYOCLONIC CEREBELLAR DYSSNERGIA ID#: D016697

Herpesviridae Infections

Definition: Virus diseases caused by the HERPESVIRIDAE. Annotation: GEN or unspecified; prefer specifics ID#: D006566


Definition: A spasm of the diaphragm that causes a sudden inhalation followed by rapid closure of the glottis which produces a sound. Annotation: ID#: D006606


Definition: The inflammation of a sweat gland (usually of the apocrine type). The condition can be idiopathic or occur as a result of or in association with another underlying condition. Neutrophilic eccrine hidradenitis is a relatively rare variant that has been reported in patients undergoing chemotherapy, usually for non-Hodgkin lymphomas or leukemic conditions. Annotation: inflamm of a sweat gland ID#: D016575

Hidradenitis Suppurativa

Definition: A chronic suppurative and cicatricial disease of the apocrine glands occurring chiefly in the axillae in women and in the groin and anal regions in men. It is characterized by poral occlusion with secondary bacterial infection, evolving into abscesses which eventually rupture. As the disease becomes chronic, ulcers appear, sinus tracts enlarge, fistulas develop, and fibrosis and scarring become evident. Hormonal mechanisms are expected in its pathogenesis. Annotation: bact skin dis ID#: D017497


Definition: A cystic form of sweat gland adenoma (ADENOMA, SWEAT GLAND). It is produced by the cystic proliferation of apocrine secretory glands. It is not uncommon, occurring in adult life in no particular age group, with males and females equally affected. The commonest site is around the eye, particularly lateral to the outer canthus. It is cured by surgical removal. (Stedman, 25th ed; Rook et al., Textbook of Dermatology, 4th ed, p2410) Annotation: /blood supply /chem /secret /ultrastruct permitted; coord IM with SWEAT GLAND NEOPLASMS (IM) ID#: D018251

High Pressure Neurological Syndrome

Definition: A syndrome related to increased atmospheric pressure and characterized by tremors, nausea, dizziness, decreased motor and mental performance, and SEIZURES. This condition may occur in those who dive deeply (c. 1000 ft) usually while breathing a mixture of oxygen and helium. The condition is associated with a neuroexcitatory effect of helium. Annotation: in divers; do not confuse with INERT GAS NARCOSIS ID#: D006610

Hip Contracture

Definition: Permanent fixation of the hip in primary positions, with limited passive or active motion at the hip joint. Locomotion is difficult and pain is sometimes present when the hip is in motion. It may be caused by trauma, infection, or poliomyelitis. (From Current Medical Information & Technology, 5th ed) Annotation: ID#: D006616

Hip Dislocation

Definition: Displacement of the femur bone from its normal position at the HIP JOINT. Annotation: ID#: D006617

Hip Dislocation, Congenital

Definition: Congenital dislocation of the hip generally includes subluxation of the femoral head, acetabular dysplasia, and complete dislocation of the femoral head from the true acetabulum. This condition occurs in approximately 1 in 1000 live births and is more common in females than in males. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; /vet permitted but congen hip disloc in dogs = HIP DYSPLASIA, CANINE: see note there ID#: D006618

Hip Dysplasia, Canine

Definition: A hereditary disease of the hip joints in dogs. Signs of the disease may be evident any time after 4 weeks of age. Annotation: congen hip disloc in dogs; don't forget check tags ANIMAL & DOGS (NIM) ID#: D006619

Hip Fractures

Definition: Fractures of the FEMUR HEAD, the FEMUR NECK (FEMORAL NECK FRACTURES), the trochanters, or the inter- or subtrochanteric region. Excludes fractures of the acetabulum and fractures of the femoral shaft below the subtrochanteric region (FEMORAL FRACTURES). Annotation: GEN or unspecified; note X refs: fract below subtrochant = FEMORAL FRACTURES; FEMORAL NECK FRACTURES is available; femur head fract = FEMUR HEAD /inj (IM) + HIP FRACTURES (IM); acetabular fract = ACETABULUM /inj (IM) + FRACTURES (IM) ID#: D006620

Hip Injuries

Definition: General or unspecified injuries involving the hip. Annotation: ID#: D025981

Hippel-Lindau Disease

Definition: An autosomal dominant disorder associated with various neoplasms including central nervous system (most often cerebellar) and retinal HEMANGIOBLASTOMA, endolymphatic sac tumors, renal cell carcinoma (see CARCINOMA, RENAL CELL), renal and pancreatic cysts, HEMANGIOMA of the spinal cord, and PHEOCHROMOCYTOMA. The most common presenting manifestations are neurologic deficits associated with intracranial hemangioblastomas which may hemorrhage, causing ataxia, INTRACRANIAL HYPERTENSION, and other signs of neurologic dysfunction. (From Neurochirurgie 1998 Nov;44(4):258-66) Annotation: ID#: D006623

Hirschsprung Disease

Definition: Congenital megacolon due to absence of myenteric ganglion cells in a distal segment of the large intestine. Annotation: congen megacolon: acquired megacolon = MEGACOLON; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006627


Definition: Excess hair in females and children with an adult male pattern of distribution. The concept does not include HYPERTRICHOSIS, which is localized or generalized excess hair. Annotation: "excess hair in females & child with an adult male pattern distrib"; differentiate from HYPERTRICHOSIS, "localized or generalized excess hair" ID#: D006628

Histiocytic Disorders, Malignant

Definition: Distinctive neoplastic disorders of histiocytes. Included are acute monocytic leukemias, malignant histiocytosis (HISTIOCYTOSIS, MALIGNANT), and true histiocytic lymphomas. Annotation: GEN or unspecified; prefer specifics; do not use /blood supply /chem /second /secret /ultrastruct; do not confuse with HISTIOCYTOSIS, MALIGNANT ID#: D015620

Histiocytic Necrotizing Lymphadenitis

Definition: Development of lesions in the lymph node characterized by infiltration of the cortex or paracortex by large collections of proliferating histiocytes and complete or, more often, incomplete necrosis of lymphoid tissue. Annotation: ID#: D020042

Histiocytoma, Fibrous

Definition: A tumor composed, wholly or in part, of cells with the morphologic characteristics of histiocytes and with various fibroblastic components. There are many variants and many names. Superficially located histiocytic lesions behave benignly but deep, benign histiocytomas may invade locally into surrounding tissue. Fibrous histiocytomas can occur anywhere in the body. Superficial lesions are always cured by simple excision; a wider margin of tissue should be obtained for deep, benign types. Local recurrence is uncommon. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1356) Annotation: benign or malignant; /blood supply /chem /second /secret /ultrastruct permitted; coord IM with precoord organ/neopl term (IM) ID#: D018219


Definition: General term for the abnormal appearance of histiocytes in the blood. Based on the pathological features of the cells involved rather than on clinical findings, the histiocytic diseases are subdivided into three groups: HISTIOCYTOSIS, LANGERHANS CELL; HISTIOCYTOSIS, NON-LANGERHANS CELL; and HISTIOCYTIC DISORDERS, MALIGNANT. Annotation: "abnormal appearance of histiocytes in the blood" (usually in tissue); GEN or unspecified only; prefer specifics; do not confuse with HISTIOCYTOSIS X see HISTIOCYTOSIS, LANGERHANS-CELL ID#: D015614

Histiocytosis, Langerhans-Cell

Definition: Group of disorders of histiocyte proliferation which includes LETTERER-SIWE DISEASE; HAND-SCHUELLER-CHRISTIAN SYNDROME; and EOSINOPHILIC GRANULOMA. Langerhans cells are components of the lesions. Annotation: GEN or unspecified; prefer specifics ID#: D006646

Histiocytosis, Malignant

Definition: A rare, usually rapidly progressive disorder, characterized by abrupt onset, fever, weight loss, hepato-splenomegaly, pancytopenia, and lymphadenopathy. Annotation: do not use /blood supply /chem /second /secret /ultrastruct; do not confuse with HISTIOCYTIC DISORDERS, MALIGNANT ID#: D006647

Histiocytosis, Non-Langerhans-Cell

Definition: Group of disorders which feature accumulations of active histiocytes and lymphocytes, but where the histiocytes are not Langerhans cells. The group includes hemophagocytic lymphohistiocytosis, infection-associated hemophagocytic syndrome, sinus histiocytosis, xanthogranuloma, reticulohistiocytoma, juvenile xanthoma, xanthoma disseminatum, as well as the lipid storage diseases (sea-blue histiocyte syndrome and Niemann-Pick disease). Annotation: GEN or unspecified; prefer specifics ID#: D015616

Histiocytosis, Sinus

Definition: Benign, non-Langerhans-cell, histiocytic proliferative disorder that primarily affects the lymph nodes. It is often referred to as sinus histiocytosis with massive lymphadenopathy. Annotation: a non-Langerhans cell histiocytosis; sinus refers to the lymphatic sinuses ID#: D015618


Definition: Infecton resulting from inhalation or ingestion of spores of the fungus of the genus HISTOPLASMA, species H. capsulatum. It is worldwide in distribution and particularly common in the midwestern United States. (From Dorland, 27th ed) Annotation: fungus dis ID#: D006660

HIV Enteropathy

Definition: Chronic, well-established diarrhea (greater than one month in duration) without an identified infectious cause after thorough evaluation, in an HIV-positive individual. It is thought to be due to direct or indirect effects of HIV on the enteric mucosa. HIV enteropathy is a diagnosis of exclusion and can be made only after other forms of diarrheal illness have been ruled out. (Harrison's Principles of Internal Medicine, 13th ed, pp1607-8; Haubrich et al., Bockus Gastroenterology, 5th ed, p1155) Annotation: chronic diarrhea in HIV-positive persons ID#: D019053

HIV Infections

Definition: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS). Annotation: caused by a lentivirus; GEN or unspecified; coord IM with HIV-1 (IM) or HIV-2 (IM); note specific indentions under HIV INFECTIONS; DF: HIV INFECT ID#: D015658

HIV Seropositivity

Definition: Development of neutralizing antibodies in individuals who have been exposed to the human immunodeficiency virus (HIV/HTLV-III/LAV). Annotation: note category; HIV SERONEGATIVITY (Cat G) is also available; /diag /immunol permitted but use caution; coord IM with HIV-1 /immunol (IM) or HIV-2 /immunol (IM); do not confuse with HIV SEROPREVALENCE, an epidemiol concept; DF: HIV SEROPOS ID#: D006679

HIV Wasting Syndrome

Definition: Involuntary weight loss of greater than 10 percent associated with intermittent or constant fever and chronic diarrhea or fatigue for more than 30 days in the absence of a defined cause other than HIV infection. A constant feature is major muscle wasting with scattered myofiber degeneration. A variety of etiologies, which vary among patients, contributes to this syndrome. (From Harrison's Principles of Internal Medicine, 13th ed, p1611). Annotation: ID#: D019247


Definition: An unnaturally deep or rough quality of voice. Annotation: for other qualities of voice VOICE QUALITY & VOICE DISORDERS are available ID#: D006685

Hodgkin Disease

Definition: A malignant disease characterized by progressive enlargement of the lymph nodes, spleen, and general lymphoid tissue, and the presence of large, usually multinucleate, cells (REED-STERNBERG CELLS) of unknown origin. Annotation: neoplastic; do not use /blood supply /chem /second /secret /ultrastruct ID#: D006689

Holocarboxylase Synthetase Deficiency

Definition: The neonatal form of MULTIPLE CARBOXYLASE DEFICIENCY that is caused by a defect or deficiency in holocarboxylase synthetase. HLCS is the enzyme that covalently links biotin to the biotin dependent carboxylases (propionyl-CoA-carboxylase, pyruvate carboxylase, and beta-methylcrotonyl-CoA carboxylase). Annotation: ID#: D028922


Definition: Anterior midline brain, cranial, and facial malformations resulting from the failure of the embryonic prosencephalon to undergo segmentation and cleavage. Alobar prosencephaly is the most severe form and features anophthalmia; cyclopia; severe MENTAL RETARDATION; CLEFT LIP; CLEFT PALATE; SEIZURES; and microcephaly. Semilobar holoprosencepaly is characterized by hypotelorism, microphthalmia, coloboma, nasal malformations, and variable degrees of mental retardation. Lobar holoprosencephaly is associated with mild (or absent) facial malformations and intellectual abilities that range from mild mental retardation to normal. Holoprosencephlay is associated with CHROMOSOME ABNORMALITIES. Annotation: ID#: D016142


Definition: An autosomal recessive inborn error of methionine metabolism usually caused by a deficiency of CYSTATHIONINE BETA-SYNTHASE and associated with elevations of homocysteine in plasma and urine. Clinical features include a tall, slender habitus, SCOLIOSIS, arachnodactyly, MUSCLE WEAKNESS, genu varis, thin blond hair, malar flush, lens dislocations, an increased incidence of MENTAL RETARDATION, and a tendency to develop fibrosis of arteries, frequently complicated by CEREBROVASCULAR ACCIDENTS and MYOCARDIAL INFARCTION. (From Adams et al., Principles of Neurology, 6th ed, p979) Annotation: ID#: D006712

Hookworm Infections

Definition: Infection of humans or animals with hookworms other than those caused by the genus Ancylostoma or Necator, for which the specific terms ANCYLOSTOMIASIS and NECATORIASIS are available. Annotation: GEN: prefer specifics; New World hookworm infection = NECATORIASIS, Old World hookworm infection = ANCYLOSTOMIASIS ID#: D006725


Definition: Purulent infection of one of the sebaceous glands of Zeis along the eyelid margin (external) or of the meibomian gland on the conjunctival side of the eyelid (internal). Annotation: bact eye infect ID#: D006726

Horner Syndrome

Definition: A syndrome associated with defective sympathetic innervation to one side of the face, including the eye. Clinical features include MIOSIS; mild BLEPHAROPTOSIS; and hemifacial ANHIDROSIS (decreased sweating)(see HYPOHIDROSIS). Lesions of the BRAIN STEM; cervical SPINAL CORD; first thoracic nerve root; apex of the LUNG; CAROTID ARTERY; CAVERNOUS SINUS; and apex of the ORBIT may cause this condition. (From Miller et al., Clinical Neuro-Ophthalmology, 4th ed, pp500-11) Annotation: ID#: D006732

Horse Diseases

Definition: Diseases of domestic and wild horses of the species Equus caballus. Annotation: IM GEN or unspecified; coord IM with specific dis /vet (IM) or specific horse dis (IM); for abnormalities or injuries index under HORSES /abnorm or HORSES /inj; don't forget also HORSES (NIM) & check tag ANIMAL; DF: HORSE DIS ID#: D006734

Hot Flashes

Definition: A sudden, temporary sensation of heat predominantly experienced by some women during MENOPAUSE. (Random House Unabridged Dictionary, 2d ed) Annotation: do not confuse with FLUSHING ID#: D019584

HTLV-I Infections


HTLV-II Infections

Definition: Annotation: GEN or unspecified; consider also LEUKEMIA, T-CELL, HTLV-II-ASSOCIATED; DF: HTLV II INFECT ID#: D015491

Humeral Fractures

Definition: Annotation: fract of humerus except of proximal humerus ( = SHOULDER FRACTURES which includes humeral head, neck & tuberosities) ID#: D006810

Huntington Disease

Definition: A familial disorder inherited as an autosomal dominant trait and characterized by the onset of progressive CHOREA and DEMENTIA in the fourth or fifth decade of life. Common initial manifestations include paranoia; poor impulse control; DEPRESSION; HALLUCINATIONS; and DELUSIONS. Eventually intellectual impairment; loss of fine motor control; ATHETOSIS; and diffuse CHOREA involving axial and limb musculature develops, leading to a vegetative state within 10-15 years of disease onset. The juvenile variant has a more fulminant course including SEIZURES; ATAXIA; dementia; and chorea. (From Adams et al., Principles of Neurology, 6th ed, pp1060-4) Annotation: ID#: D006816

Hutchinson's Melanotic Freckle

Definition: A cellular subtype of malignant melanoma. It is a pigmented lesion composed of melanocytes occurring on sun-exposed skin, usually the face and neck. The melanocytes are commonly multinucleated with a "starburst" appearance. It is considered by many to be the in situ phase of lentigo maligna melanoma. Annotation: coord IM with SKIN NEOPLASMS (IM) + site (IM or NIM) if relevant ID#: D018327

Hyaline Membrane Disease

Definition: A disorder affecting newborn infants (usually premature) characterized pathologically by the development of a hyaline-like membrane lining the terminal respiratory passages. Extensive atelectasis is attributed to the lack of surfactant. (Dorland, 27th ed) Annotation: a resp distress syndrome; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; check tags HUMAN & INFANT, NEWBORN ID#: D006819

Hydatidiform Mole

Definition: A trophoblastic disease characterized by hydrops of the mesenchymal portion of the villus. Its karyotype is paternal and usually homozygotic. The tumor is indistinguishable from chorioadenoma destruens or invasive mole ( = HYDATIDIFORM MOLE, INVASIVE) except by karyotype. There is no apparent relation by karyotype to CHORIOCARCINOMA. Hydatidiform refers to the presence of the hydropic state of some or all of the villi (Greek hydatis, a drop of water). Annotation: neoplastic; see MeSH definition: has nothing to do with hydatid cyst ( = ECHINOCOCCOSIS or specific); /blood supply /chem /secret /ultrastruct permitted; coord IM with UTERINE NEOPLASMS (IM); check the tags FEMALE & PREGNANCY ID#: D006828

Hydatidiform Mole, Invasive

Definition: A tumor or tumor-like process invading the myometrium, and characterized by trophoblastic hyperplasia and persistence of placental villous structures. It commonly results from complete hydatidiform mole but may do so from partial hydatidiform mole. Invasive mole may metastasize but it does not exhibit the progression of a true cancer, and it may regress spontaneously. (Holland et al., Cancer Medicine, 3d ed, p1691) Annotation: /blood supply /chem /second /secret /ultrastruct permitted; coord IM with UTERINE NEOPLASMS (IM); check the tags FEMALE & PREGNANCY ID#: D002820


Definition: A congenital condition where the greater portions of the cerebral hemispheres and CORPUS STRIATUM are replaced by CSF and glial tissue. The meninges and the skull are well formed, which is consistent with earlier normal embryogenesis of the telencephalon. Bilateral occlusions of the internal carotid arteries in utero is a potential mechanism. Clinical features include intact brainstem reflexes without evidence of higher cortical activity. (Menkes, Textbook of Child Neurology, 5th ed, p307) Annotation: ID#: D006832


Definition: Accumulation of watery fluid in the cavity of a joint. (Dorland, 27th ed) Annotation: fluid in a joint cavity ID#: D006833

Hydroa Vacciniforme

Definition: A vesicular and bullous eruption having a tendency to recur in summer during childhood and commonly appearing on sun-exposed skin. The lesions are surrounded by an erythematous zone and resemble a vaccination. (From Dorland, 27th ed) Annotation: a vesiculobullous skin dis on sun-exposed skin ID#: D006837


Definition: A circumscribed collection of fluid, especially a collection of fluid in the tunica vaginalis of the testicle or along the spermatic cord. (Dorland, 27th ed) Annotation: collection of fluid in testis or along spermatic cord; "vaginal hydrocele" is of the tunica vaginalis of the testis, not of the vagina; hydrocele of Nuck's canal is a watery dilatation of the processus vaginalis peritonei (also called Nuck's canal): index under PERITONEAL DISEASES ID#: D006848


Definition: Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, INTRACRANIAL HYPERTENSION; HEADACHE; lethargy; URINARY INCONTINENCE; and ATAXIA (and in infants macrocephaly). This condition may be caused by obstruction of cerebrospinal fluid pathways due to neurologic abnormalities, INTRACRANIAL HEMORRHAGES; CENTRAL NERVOUS SYSTEM INFECTIONS; BRAIN NEOPLASMS; CRANIOCEREBRAL TRAUMA; and other conditions. Impaired resorption of cerebrospinal fluid from the arachnoid villi results in a communicating form of hydrocephalus. Hydrocephalus ex-vacuo refers to ventricular dilation that occurs as a result of brain substance loss from CEREBRAL INFARCTION and other conditions. Annotation: ID#: D006849

Hydrocephalus, Normal Pressure

Definition: A form of compensated hydrocephalus characterized clinically by a slowly progressive gait disorder (see GAIT DISORDERS, NEUROLOGIC), progressive intellectual decline, and URINARY INCONTINENCE. Spinal fluid pressure tends to be in the high normal range. This condition may result from processes which interfere with the absorption of CSF including SUBARACHNOID HEMORRHAGE, chronic MENINGITIS, and other conditions. (From Adams et al., Principles of Neurology, 6th ed, pp631-3) Annotation: ID#: D006850


Definition: A distention of the pelvis and calices of the kidney with urine, as a result of obstruction of the ureter, with accompanying atrophy of the parenchyma of the organ. (Dorland, 27th ed) Annotation: kidney distention with urine ID#: D006869


Definition: Congenital open-angle glaucoma that results from dysgenesis of the angle structures accompanied by increased intraocular pressure and enlargement of the eye. Treatment is both medical and surgical. Annotation: a type of open-angle glaucoma; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006871


Definition: A collection of fluid and gas within the pleural cavity. (Dorland, 27th ed) Annotation: pneumothorax with fluid in pleural cavity ID#: D006872

Hydrops Fetalis

Definition: Edema of the entire body due to abnormal accumulation of serous fluid in the tissues, associated with severe anemia and occurring in ERYTHROBLASTOSIS, FETAL. Annotation: edema of entire body of fetus in fetal erythroblastosis; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D015160


Definition: A collection of watery fluid in the pleural cavity. (Dorland, 27th ed) Annotation: fluid in pleural cavity ID#: D006876


Definition: Infection with tapeworms of the genus Hymenolepis. Annotation: tapeworm infect ID#: D006925


Definition: An abnormally disproportionate increase in the sensation of loudness in response to auditory stimuli of normal volume. COCHLEAR DISEASES; VESTIBULOCOCHLEAR NERVE DISEASES; FACIAL NERVE DISEASES; STAPES SURGERY; and other disorders may be associated with this condition. Annotation: ID#: D012001


Definition: An abnormality of electrolyte function caused by excessive secretion of aldosterone by the adrenal cortex. (Dorland, 27th ed) Annotation: caused by adrenal hyperfunction; do not confuse with HYPOALDOSTERONISM ID#: D006929


Definition: An increased sensation to painful stimuli that may follow damage to soft tissue containing NOCICEPTORS or injury to a peripheral nerve. Hyperalgesia can occur both at the site of tissue damage (primary hyperalgesia) and in the surrounding undamaged areas (secondary hyperalgesia). (Kandel et al., Principles of Neural Science, 3d ed, p386) Annotation: coord with TOUCH or HEAT if pertinent ID#: D006930


Definition: Metabolic disorder characterized by elevated level of ammonia in blood. Annotation: ID#: D022124


Definition: A state characterized or caused by an excessive secretion of androgens by the adrenal cortex, ovaries, or testes. The clinical significance in males is negligible, so the term is used most commonly with reference to the female. The common manifestations in women are hirsutism and virilism. It is often caused by ovarian disease (particularly the POLYCYSTIC OVARY SYNDROME) and by adrenal diseases (particularly ADRENAL GLAND HYPERFUNCTION). Annotation: GEN or unspecified; prefer specific manifestation such as HIRSUTISM; VIRILISM; etc. ID#: D017588


Definition: A rare autosomal recessive disorder of the urea cycle. It is caused by a deficiency of the hepatic enzyme type I ARGINASE. Arginine is elevated in the blood and cerebrospinal fluid, and periodic hyperammonemia may occur. Disease onset is usually in infancy or early childhood. Clinical manifestations include seizures, microcephaly, progressive mental impairment, hypotonia, ataxia, spastic diplegia, and quadriparesis. (From Hum Genet 1993 Mar;91(1):1-5; Menkes, Textbook of Child Neurology, 5th ed, p51) Annotation: ID#: D020162


Definition: Pathologic process consisting of an abnormal increase in the amount of BILIRUBIN in the circulating blood, which may result in JAUNDICE. Annotation: ID#: D006932

Hyperbilirubinemia, Hereditary

Definition: Inborn errors of bilirubin metabolism resulting in excessive amounts of bilirubin in the circulating blood, either because of increased bilirubin production or because of delayed clearance of bilirubin from the blood. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006933


Definition: Abnormally high level of calcium in the blood. Annotation: high blood calcium levels; do not confuse with HYPOCALCEMIA; X ref is also called Burnett's syndrome or milk-drinker's syndrome ID#: D006934


Definition: A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood. Annotation: CARBON DIOXIDE/blood is also available ID#: D006935


Definition: A regressive change of teeth characterized by excessive development of secondary cementum on the tooth surface. It may occur on any part of the root, but the apical two-thirds are most commonly affected. (Dorland, 27th ed) Annotation: excessive develop of secondary cementum on tooth surface ID#: D006936


Definition: Abnormally high levels of cholesterol in the blood. Annotation: high blood cholesterol levels ID#: D006937

Hypercholesterolemia, Familial

Definition: A familial disorder characterized by increased plasma concentration of cholesterol carried in low density lipoproteins (LDL) and by a deficiency in a cell surface receptor which regulates LDL degradation and cholesterol synthesis. Annotation: do not coord with INFANT, NEWBORN, DISEASES ID#: D006938

Hyperemesis Gravidarum

Definition: Pernicious vomiting of pregnancy. (Dorland, 27th ed) Annotation: excessive vomiting in pregn; check tags FEMALE & PREGNANCY ID#: D006939


Definition: The presence of an increased amount of blood in a part or organ. (Stedman, 25th ed) Annotation: increased amount of blood in an organ ID#: D006940

Hypereosinophilic Syndrome

Definition: A heterogeneous group of disorders with the common feature of prolonged eosinophilia of unknown cause and associated organ system dysfunction, including the heart, central nervous system, kidneys, lungs, gastrointestinal tract, and skin. There is a massive increase in the number of eosinophils in the blood, mimicking leukemia, and extensive eosinophilic infiltration of the various organs. It is often referred to as idiopathic. Annotation: do not confuse X ref LOEFFLER'S ENDOCARDITIS with LOEFFLER SYNDROME see PULMONARY EOSINOPHILIA ID#: D017681


Definition: Increased sensitivity to cutaneous stimulation due to a diminished threshold or an increased response to stimuli. Annotation: do not confuse with HYPESTHESIA, diminished sensitivity; coord with TOUCH or HEAT if pertinent ID#: D006941


Definition: An excess of GAMMA-GLOBULINS in the blood. It is seen frequently in chronic infectious diseases. (Dorland, 27th ed) Annotation: coord IM with specific immunoglobulin (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G or IMMUNOGLOBULIN M) (IM); for light-chain gammopathy see TN 226; for heavy-chain gammopathy index under HEAVY CHAIN DISEASE (IM) + specific heavy chain (IMMUNOGLOBULIN, ALPHA CHAIN; IMMUNOGLOBULIN, DELTA CHAIN, etc.) (NIM) (TN 226) ID#: D006942


Definition: Abnormally increased content of sugar in the blood. (Dorland, 27th ed) Annotation: high blood sugar levels; do not confuse with HYPOGLYCEMIA; obese hyperglycemic mice go under MICE, OBESE: do not index under HYPERGLYCEMIA or OBESITY unless particularly discussed as disease; Somogyi effect or rebound hyperglycemia: index under HYPERGLYCEMIA /chem ind + DIABETES MELLITUS /drug ther + INSULIN /adv eff; "induced hyperglycemia" in disease states or physiol studies: index under BLOOD GLUCOSE, not HYPERGLYCEMIA ID#: D006943

Hyperglycemic Hyperosmolar Nonketotic Coma

Definition: A syndrome consisting of extreme hyperglycemia, serum hyperosmolarity and dehydration in the absence of ketosis and acidosis. Annotation: a type of diabetic coma; not for nonketotic hyperglycinemia (= AMINO ACID METAB INBORN ERR + GLYCINE/metab); DF: HHNC or HHNK ID#: D006944

Hyperglycinemia, Nonketotic

Definition: An autosomal recessive metabolic disorder caused by deficiencies in the mitochondrial GLYCINE cleavage system; an enzyme system with four components: P-, T-, H-, and L-proteins. Deficiency of the P-protein is the most prevalent form. Neonatal and juvenile presentations have been reported. Neonatal onset is more common and may be fatal. Clinical features include SEIZURES; hypotonia; APNEA; and COMA. When the illness presents in childhood there tends to be an associated progressive DEMENTIA accompanied by extrapyramidal signs. (Menkes, Textbook of Child Neurology, 5th ed, p46; Jpn J Hum Genet 1997 Mar;42(1):13-22) Annotation: ID#: D020158


Definition: Excessive sweating. In the localized type, the most frequent sites are the palms, soles, axillae, inguinal folds, and the perineal area. Its chief cause is thought to be emotional. Generalized hyperhidrosis may be induced by a hot, humid environment, by fever, or by vigorous exercise. Annotation: excessive sweating; do not confuse with HYPOHIDROSIS, reduced sweating ID#: D006945


Definition: An inborn error of methionone metabolism which produces an excess of homocysteine in the blood. It is often caused by a deficiency of CYSTATHIONINE BETA-SYNTHASE and is a risk factor for coronary vascular disease. Annotation: ID#: D020138


Definition: Excessively high blood insulin levels. It should be differentiated from HYPERINSULINISM, excessive secretion of insulin by the pancreatic islets, in that hyperinsulinemia may be the result of a variety of conditions, such as obesity and pregnancy. (From Dorland, 28th ed) Annotation: excessively high blood insulin levels from a variety of clin or exper conditions: do not confuse with HYPERINSULINISM, excessive insulin secretion by islet cells ID#: D019171


Definition: Excessive secretion of INSULIN by the pancreatic islets, resulting in hypoglycemia. (Dorland, 28th ed) Annotation: excessive insulin secretion by pancreas: do not confuse with HYPERINSULINEMIA, excessively high blood insulin levels resulting from a variety of clinical & exper conditions ID#: D006946


Definition: Abnormally high potassium concentration in the blood, most often due to defective renal excretion. It is characterized clinically by electrocardiographic abnormalities (elevated T waves and depressed P waves, and eventually by atrial asystole). In severe cases, weakness and flaccid paralysis may occur. (Dorland, 27th ed) Annotation: high blood potassium levels; do not confuse with HYPOKALEMIA ID#: D006947

Hyperkeratosis, Epidermolytic

Definition: A form of congenital ichthyosis inherited as an autosomal dominant trait and characterized by erythroderma and severe hyperkeratosis. It is manifested at birth by blisters followed by the appearance of thickened, horny, verruciform scales over the entire body, but accentuated in flexural areas. Annotation: a form of congen ichthyosis; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D017488


Definition: Excessive movement of muscles of the body as a whole, which may be associated with organic or psychological disorders. Annotation: human & animal; MOTOR ACTIVITY is also available: see note there; do not confuse with MYOKYMIA or ISAACS SYNDROME ID#: D006948


Definition: An excess of lipids in the blood. Annotation: high blood lipid levels; for X ref DYSLIPIDEMIA, prefer specific indentions; /drug ther: consider also ANTILIPEMIC AGENTS ID#: D006949

Hyperlipidemia, Familial Combined

Definition: A disorder genetically distinct from the other inherited hyperlipidemias characterized by the type II or type IV lipoprotein pattern (the pattern may change from time to time and the lipid level may be normal at one time and abnormal at another time). Annotation: familial or acquired ID#: D006950


Definition: Metabolic disease characterized by excess plasma LIPOPROTEINS. Annotation: do not confuse with HYPOLIPOPROTEINEMIA; familial or acquired; GEN or unspecified: specific Types I-V are available ID#: D006951

Hyperlipoproteinemia Type III

Definition: A rather uncommon form of familial hyperlipemia characterized by the presence of lipoproteins of abnormal composition. The main abnormal lipoproteins are called beta-VLDL and have a different apoprotein content and a higher proportion of cholesterol relative to triglyceride than normal VLDL. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006952

Hyperlipoproteinemia Type IV

Definition: A familial disorder characterized by an isolated elevation in the plasma level of endogenously synthesized triglyceride carried in VLDL. It is considered to be an autosomal dominant trait. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006953

Hyperlipoproteinemia Type V

Definition: A severe familial adult-onset hypertriglyceridemia different from that due to lipoprotein lipase deficiency. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006954


Definition: A group of inherited metabolic disorders which have in common elevations of serum LYSINE levels. Enzyme deficiencies of alpha-aminoadipic semialdehyde dehydrogenase and the SACCHAROPINE DEHYDROGENASES have been associated with hyperlysinemia. Clinical manifestations include mental retardation, recurrent emesis, hypotonia, lethargy, diarrhea, and developmental delay. (From Menkes, Textbook of Child Neurology, 5th ed, p56) Annotation: ID#: D020167


Definition: Excessive amount of sodium in the blood. (Dorland, 27th ed) Annotation: high blood sodium levels; do not confuse with HYPONATREMIA ID#: D006955


Definition: A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed) Annotation: refractive error; note X ref ID#: D006956


Definition: Increase in the mass of bone per unit volume. Annotation: ID#: D015576

Hyperostosis Frontalis Interna

Definition: Thickening of the inner table of the frontal bone, which may be associated with hypertrichosis and obesity. It most commonly affects women near menopause. Annotation: frontalis refers to frontal bone of skull ID#: D006957

Hyperostosis, Cortical, Congenital

Definition: A disease of young infants characterized by soft tissue swellings over the affected bones, fever, and irritability, and marked by periods of remission and exacerbation. (Dorland, 27th ed) Annotation: cortical refers to cortex of bone; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006958

Hyperostosis, Diffuse Idiopathic Skeletal

Definition: A disease of elderly men characterized by large osteophytes that bridge vertebrae and ossification of ligaments and tendon insertions. Annotation: DF: DISH ID#: D004057

Hyperostosis, Sternocostoclavicular

Definition: A rare, benign rheumatologic disorder or syndrome characterized by hyperostosis and soft tissue ossification between the clavicles and the anterior part of the upper ribs. It is often associated with the dermatologic disorder palmoplantar pustulosis, particularly in Japan. Careful diagnosis is required to distinguish it from psoriatic arthritis, OSTEITIS DEFORMANS, and other diseases. Spondylitis of pustulosis palmaris et plantaris is one of the possible causes; also, evidence suggests one origin may be bone infection. Bone imaging is especially useful for diagnosis. It was originally described by Sonozaki in 1974. Annotation: a type of rheum dis; DF: SCCH ID#: D015218


Definition: Excretion of an excessive amount of oxalate in the urine. Annotation: HYPEROXALURIA, PRIMARY is also available ID#: D006959

Hyperoxaluria, Primary

Definition: Either of two genetic disorders characterized by urinary excretion of large amounts of oxalate, with nephrolithiasis, nephrocalcinosis, early onset of renal failure, and often a generalized deposit of calcium oxalate, resulting from a defect in glyoxalate metabolism. Annotation: do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006960


Definition: An abnormal increase in the amount of oxygen in the tissues and organs. Annotation: restrict to dis or clin state in humans or higher animals: do not confuse with hyperoxic state in lower animals or micro-organisms ( = OXYGEN or AEROBIOSIS); do not confuse with HYPOXIA see ANOXIA ID#: D018496


Definition: Abnormally increased activity of the parathyroid glands, which may be primary or secondary (HYPERPARATHYRODISM, SECONDARY). Primary hyperparathyroidism is associated with neoplasia or hyperplasia. The excess of parathyroid hormone leads to alteration in function of bone, renal tubules, and gastrointestinal mucosa. (Dorland, 27th ed) Annotation: ID#: D006961

Hyperparathyroidism, Secondary

Definition: Annotation: ID#: D006962


Definition: Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Annotation: do not confuse with HYPOPIGMENTATION ID#: D017495


Definition: Inappropriate secretion of anterior pituitary gland hormones. The most common hormones involved in over-secretion are SOMATOTROPIN (which may cause ACROMEGALY) and PROLACTIN (which results in HYPERPROLACTINEMIA). THYROTROPIN; luteinizing hormone (LH); CORTICOTROPIN; and FOLLICLE STIMULATING HORMONE may also be secreted at inappropriate levels. Hypersecretion syndromes are frequently associated with the presence of a pituitary ADENOMA (see also PITUITARY NEOPLASMS). Annotation: coord with specific hormone/secret if pertinent ID#: D006964


Definition: An increase in the number of cells in a tissue or organ, not due to tumor formation. It differs from HYPERTROPHY, which is an increase in bulk without an increase in the number of cells. Annotation: see MeSH definition for differentiation from HYPERTROPHY; NIM; coord with organ /pathol (IM); also available are ENDOMETRIAL HYPERPLASIA; GINGIVAL HYPERPLASIA & THYMUS HYPERPLASIA; congen adrenal hyperplasia = ADRENAL HYPERPLASIA, CONGENITAL but non-congen adrenal hyperplasia = ADRENAL GLANDS /pathol (IM) + HYPERPLASIA (NIM); note HYPERPLASIA, REACTIVE LYMPHOID see PSEUDOLYMPHOMA; GIANT LYMPH NODE HYPERPLASIA is also available ID#: D006965


Definition: Increased levels of prolactin in the blood, which may be associated with AMENORRHEA and GALACTORRHEA. Relatively common etiologies include PROLACTINOMA, medication effect, KIDNEY FAILURE, granulomatous diseases of the pituitary gland, and disorders which interfere with the hypothalamic inhibition of prolactin release. Ectopic (non-pituitary) production of prolactin may also occur. (From Joynt, Clinical Neurology, 1992, Ch36, pp77-8) Annotation: ID#: D006966


Definition: Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen. Annotation: IM; use qualif with caution; /drug ther: consider also ANTI-ALLERGIC AGENTS; atopic = HYPERSENSITIVITY, IMMEDIATE; to food = FOOD HYPERSENSITIVITY; to light = PHOTOSENSITIVITY DISORDERS; RESPIRATORY HYPERSENSITIVITY is also available; in occup or environ exposure MULTIPLE CHEMICAL SENSITIVITY is also available ID#: D006967

Hypersensitivity, Delayed

Definition: An increased reactivity to specific antigens mediated not by antibodies but by cells. Annotation: IM; use qualif with caution; /chem ind: coord IM with DRUG HYPERSENSITIVITY or specifics (IM) ID#: D006968

Hypersensitivity, Immediate

Definition: Hypersensitivity reactions which occur within minutes of exposure to challenging antigen due to the release of histamine which follows the antigen-antibody reaction and causes smooth muscle contraction and increased vascular permeability. Annotation: /chem ind: coord with DRUG HYPERSENSITIVITY or specifics ID#: D006969


Definition: Condition characterized by splenomegaly, some reduction in the number of circulating blood cells in the presence of a normal or hyperactive bone marrow, and the potential for reversal by splenectomy. Annotation: increase in splenic hemolytic function: do not confuse with SPLENOMEGALY, increase in spleen size ID#: D006971


Definition: Abnormal increase in the interorbital distance due to overdevelopment of the lesser wings of the sphenoid. Annotation: a form of craniofacial dysostosis; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006972


Definition: Persistently high arterial blood pressure. Currently accepted threshold levels are 140 mm Hg systolic and 90 mm Hg diastolic pressure. Annotation: only blood pressure; not for intracranial or intraocular pressure; relation to BLOOD PRESSURE: Manual 23.27+; /drug ther: consider also ANTIHYPERTENSIVE AGENTS; Goldblatt kidney or Goldblatt hypertension is HYPERTENSION, GOLDBLATT see HYPERTENSION, RENOVASCULAR; hypertension with kidney dis is probably HYPERTENSION, RENAL, not HYPERTENSION; EPH (Edema, Proteinuria, Hypertension) = GESTOSIS, EPH & do not index under HYPERTENSION unless it is particularly discussed; venous hypertension: index under VENOUS PRESSURE (IM) & do not coord with HYPERTENSION ID#: D006973

Hypertension, Malignant

Definition: Severe hypertension characterized by papilledema and necrosis of small arteries and arterioles. The diastolic pressure is generally greater than 130 mm Hg. Annotation: malignant does not refer to neoplasm: refers to severe hypertension with papilledema & arterial necrosis ID#: D006974

Hypertension, Portal

Definition: Abnormally increased pressure in the portal venous system; frequently seen in cirrhosis of the liver and in other conditions which cause obstruction of the portal vein. Annotation: increased pressure in portal venous system ID#: D006975

Hypertension, Pulmonary

Definition: Increased pressure within the pulmonary circulation, usually secondary to cardiac or pulmonary disease. Annotation: increased pressure within pulm circ; DF: HYPERTENSION PULM ID#: D006976

Hypertension, Renal

Definition: Hypertension due to renal diseases, especially chronic parenchymal disease. Hypertension as a result of compression or obstruction of the renal artery or its branches is HYPERTENSION, RENOVASCULAR. Annotation: hypertension caused by kidney dis; coord IM with specific kidney dis (IM) if pertinent; Goldblatt hypertension or Goldblatt kidney is HYPERTENSION, GOLDBLATT see HYPERTENSION, RENOVASCULAR ID#: D006977

Hypertension, Renovascular

Definition: Hypertension due to compression or obstruction of the renal artery or its branches. Annotation: hypertension caused by compression or obstruct of renal artery or branches: do not routinely index also under RENAL ARTERY or RENAL ARTERY OBSTRUCTION ID#: D006978

Hypertensive Encephalopathy

Definition: Brain dysfunction or damage resulting from MALIGNANT HYPERTENSION, usually associated with a diastolic blood pressure in excess of 125 mmHg. Clinical manifestations include headache, nausea, emesis, seizures, altered mental status (in some cases progressing to COMA); PAPILLEDEMA; and RETINAL HEMORRHAGE. Focal neurologic signs may develop. Pathologically, this condition may be associated with the formation of ischemic lesions in the brain (BRAIN ISCHEMIA). Annotation: ID#: D020343


Definition: Excessive functional activity of the thyroid gland. Annotation: THYROTOXICOSIS & THYROID CRISIS are available: do not make a diagnosis: use term of author ID#: D006980


Definition: Excess of thyroxine in the blood. Annotation: ID#: D006981


Definition: Localized or generalized excess hair. The concept does not include HIRSUTISM, which is excess hair in females and children with an adult male pattern of distribution. Annotation: "localized or generalized excess hair": differentiate from HIRSUTISM, "excess hair in females & child with an adult male pattern distrib"; do not confuse with HYPOTRICHOSIS ID#: D006983


Definition: Condition of elevated triglyceride concentration in the blood; an inherited form occurs in familial hyperlipoproteinemia IIb and HYPERLIPOPROTEINEMIA TYPE IV. It has been linked to higher risk of heart disease and arteriosclerosis. Annotation: high blood triglyceride levels; consider also HYPERTRIGLYCERIDEMIA, FAMILIAL see HYPERLIPOPROTEINEMIA TYPE IV & the adult-onset hypertriglyceridemia of HYPERLIPOPROTEINEMIA TYPE V & the triglyceride-rich lipoproteins of LIPOPROTEIN LIPASE DEFICIENCY, FAMILIAL ID#: D015228


Definition: General increase in bulk of a part or organ, not due to tumor formation, nor to an increase in the number of cells. Annotation: NIM; GEN or unspecified: prefer many precoord organ/hypertrophy terms, like PROSTATIC HYPERTROPHY; see MeSH definition for differentiation from HYPERPLASIA; coord with organ /pathol ID#: D006984

Hypertrophy, Left Ventricular

Definition: Enlargement of the left ventricle of the heart. This increase in ventricular mass is attributed to sustained abnormal pressure or volume loads and is a contributor to cardiovascular morbidity and mortality. Annotation: ID#: D017379

Hypertrophy, Right Ventricular

Definition: Enlargement of the right ventricle of the heart. This increase in ventricular mass is often attributed to pulmonary hypertension and is a contributor to cardiovascular morbidity and mortality. Annotation: ID#: D017380


Definition: A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide. Annotation: respiratory, not environmental; hyperventilation syndrome: coord IM with /psychol + emotional aspect (IM or NIM) ID#: D006985

Hypervitaminosis A

Definition: A symptom complex resulting from ingestion of excessive amounts of vitamin A. Annotation: excessive intake of vitamin A ID#: D006986


Definition: Absent or reduced sensitivity to cutaneous stimulation. Annotation: do not confuse with HYPERESTHESIA, increased sensitivity; coord with TOUCH or HEAT if pertinent ID#: D006987


Definition: Bleeding in the anterior chamber of the eye. Annotation: ID#: D006988


Definition: Aldosterone deficiency, usually associated with hypoadrenalism, and characterized by hypotension, dehydration, and a tendency to excrete excessive amounts of sodium. A selective aldosterone deficiency resulting from low renin production is called hyporeninemic hypoaldosteronism. (From Dorland, 28th ed; Stedman, 26th ed) Annotation: caused by adrenal hypofunction; do not confuse with HYPERALDOSTERONISM or PSEUDOHYPOALDOSTERONISM ID#: D006994


Definition: A disease in which the low density lipoprotein (beta-lipoprotein) concentrations are far below normal. Annotation: low blood beta-lipoprotein levels; do not confuse with ABETALIPOPROTEINEMIA; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D006995


Definition: Reduction of the blood calcium below normal. Manifestations include hyperactive deep tendon reflexes, Chvostek's sign, muscle and abdominal cramps, and carpopedal spasm. (Dorland, 27th ed) Annotation: low blood calcium levels; do not confuse with HYPERCALCEMIA ID#: D006996


Definition: Clinical manifestation consisting of a deficiency of carbon dioxide in arterial blood. Annotation: CARBON DIOXIDE/blood is also available ID#: D016857


Definition: Infestation with larvae of the genus Hypoderma, the warble fly. Annotation: Hypoderma is indexed under DIPTERA ID#: D007000

Hypoglossal Nerve Diseases

Definition: Diseases of the twelfth cranial (hypoglossal) nerve or nuclei. The nuclei and fascicles of the nerve are located in the medulla, and the nerve exits the skull via the hypoglossal foramen and innervates the muscles of the tongue. Lower brain stem diseases, including ischemia and MOTOR NEURON DISEASES may affect the nuclei or nerve fascicles. The nerve may also be injured by diseases of the posterior fossa or skull base. Clinical manifestations include unilateral weakness of tongue musculature and lingual dysarthria, with deviation of the tongue towards the side of weakness upon attempted protrusion. Annotation: neopl: coord IM with CRANIAL NERVE NEOPLASMS (IM) + histol type of neopl (IM) ID#: D020437


Definition: An abnormally diminished concentration of glucose in the blood, which may lead to tremulousness, cold sweat, piloerection, hypothermia, and headache, accompanied by irritability, confusion, hallucinations, bizarre behavior, and ultimately, convulsions and coma. (Dorland, 27th ed) Annotation: low blood sugar levels; do not confuse with HYPERGLYCEMIA ID#: D007003


Definition: Condition resulting from or characterized by abnormally decreased functional activity of the gonads, with retardation of growth and sexual development. Annotation: for male or female; do not routinely interpret hypogonadism in male as EUNUCHISM: use terminology of author ID#: D007006


Definition: Abnormally diminished or absent perspiration. Both generalized and segmented (reduced or absent sweating in circumscribed locations) forms of the disease are usually associated with other underlying conditions. Annotation: diminished sweating; do not confuse with HYPERHIDROSIS, excessive sweating ID#: D007007


Definition: Abnormally low potassium concentration in the blood. It may result from potassium loss by renal secretion or by the gastrointestinal route, as by vomiting or diarrhea. It may be manifested clinically by neuromuscular disorders ranging from weakness to paralysis, by electrocardiographic abnormalities (depression of the T wave and elevation of the U wave), by renal disease, and by gastrointestinal disorders. (Dorland, 27th ed) Annotation: low blood potassium levels; do not confuse with HYPERKALEMIA ID#: D007008

Hypokalemic Periodic Paralysis

Definition: An autosomal dominant familial disorder characterized by recurrent episodes of skeletal muscle weakness associated with falls in serum potassium levels. The condition usually presents in the first or second decade of life with attacks of trunk and leg paresis during sleep or shortly after awakening. Symptoms may persist for hours to days and generally are precipitated by exercise or a meal high in carbohydrates. (Adams et al., Principles of Neurology, 6th ed, p1483) Annotation: ID#: D020514


Definition: Slow or diminished movement of body musculature. It may be associated with BASAL GANGLIA DISEASES; MENTAL DISORDERS; prolonged inactivity due to illness; experimental protocols used to evaluate the physiologic effects of immobility; and other conditions. Annotation: ID#: D018476


Definition: The presence of abnormally low levels of lipoproteins in the serum. Annotation: low blood lipoprotein levels; do not confuse with HYPERLIPOPROTEINEMIA; hypolipoproteinemia, VLDL (hypoprebetalipoproteinemia): coord IM with LIPOPROTEINS, VLDL /blood (IM); hypolipoproteinemia, HDL (hypoalphalipoproteinemia): coord IM with LIPOPROTEINS, HDL/blood (IM); hypolipoproteinemia, LDL = HYPOBETALIPOPROTEINEMIA; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES; for near absence of apolipoprotein B, use ABETALIPOPROTEINEMIA ID#: D007009


Definition: Deficiency of sodium in the blood; salt depletion. (Dorland, 27th ed) Annotation: low blood sodium levels; do not confuse with HYPERNATREMIA ID#: D007010


Definition: Annotation: ID#: D007011

Hypopharyngeal Neoplasms

Definition: Tumors or cancer of the HYPOPHARYNX. Annotation: coord IM with histol type of neopl (IM) ID#: D007012


Definition: A genetic metabolic disorder resulting from serum and bone alkaline phosphatase deficiency leading to hypercalcemia, ethanolamine phosphatemia, and ethanolamine phosphaturia. Clinical manifestations include severe skeletal defects resembling vitamin D-resistant rickets, failure of the calvarium to calcify, dyspnea, cyanosis, vomiting, constipation, renal calcinosis, failure to thrive, disorders of movement, beading of the costochondral junction, and rachitic bone changes. (From Dorland, 27th ed) Annotation: defic of blood phosphatases; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D007014


Definition: An abnormally decreased level of phosphates in the blood. The manifestations include hemolysis, lassitude, weakness, and convulsions. It may be found in hyperparathyroidism, rickets, osteomalacia, and several renal tubular abnormalities. (Dorland, 27th ed) Annotation: a clin entity (abnorm decreased blood phosphates): not for transient decreased blood phosphate levels ( = PHOSPHATES /blood); do not use /congen ( = HYPOPHOSPHATEMIA, FAMILIAL) ID#: D017674

Hypophosphatemia, Familial

Definition: Familial disorder characterized by hypophosphatemia associated with decreased renal tubular reabsorption of inorganic phosphorus. It is sometimes associated with osteomalacia or rickets which do not respond to the usual doses of vitamin D. Annotation: a clin entity: not for decreased blood phosphate levels ( = PHOSPHATES /blood); do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D007015


Definition: A condition caused by a deficiency or a loss of melanin pigmentation in the epidermis, also known as hypomelanosis. Hypopigmentation can be localized or generalized, and may result from genetic defects, trauma, inflammation, or infections. Annotation: do not confuse with HYPERPIGMENTATION ID#: D017496


Definition: Diminution or cessation of secretion of one or more hormones from the anterior pituitary gland (including LH; FOLLICLE STIMULATING HORMONE; SOMATOTROPIN; and CORTICOTROPIN). This may result from surgical or radiation ablation, non-secretory PITUITARY NEOPLASMS, metastatic tumors, infarction, PITUITARY APOPLEXY, infiltrative or granulomatous processes, and other conditions. Annotation: ID#: D007018

Hypoplastic Left Heart Syndrome

Definition: A condition characterized by underdevelopment of the left cardiac chambers, atresia or stenosis of the aorta or mitral valve or both, and hypoplasia of the aorta. These anomalies are a common cause of heart failure in early infancy. Annotation: a congen heart defect; do not use /congen & do not coord with INFANT, NEWBORN, DISEASES ID#: D018636


Definition: Annotation: ID#: D007019


Definition: Absence or reduced levels of prothrombin in the blood. Annotation: ID#: D007020


Definition: A developmental anomaly in the male in which the urethra opens on the underside of the penis or on the perineum. Annotation: a urethral-penile abnorm; do not use /congen & do not coord with INFANT, NEWBORN, DISEASE ID#: D007021


Definition: Abnormally low blood pressure seen in shock but not necessarily indicative of it. (Dorland, 28th ed) Annotation: only blood pressure; not for intracranial pressure; relation to BLOOD PRESSURE: Manual 23.27+ ID#: D007022

Hypotension, Orthostatic

Definition: A drop in blood pressure upon standing or after standing motionless in a static position. Annotation: ID#: D007024

Hypothalamic Diseases

Definition: Neoplastic, inflammatory, infectious, and other diseases of the hypothalamus. Clinical manifestations include appetite disorders; AUTONOMIC NERVOUS SYSTEM DISEASES; SLEEP DISORDERS; behavioral symptoms related to dysfunction of the LIMBIC SYSTEM; and neuroendocrine disorders. Annotation: GEN: prefer specifics; coord IM with specific part of hypothalamus (IM) ID#: D007027

Hypothalamic Neoplasms

Definition: Benign and malignant tumors of the HYPOTHALAMUS. Pilocytic astrocytomas and hamartomas are relatively frequent histologic types. Neoplasms of the hypothalamus frequently originate from adjacent structures, including the OPTIC CHIASM, optic nerve (see OPTIC NERVE NEOPLASMS), and pituitary gland (see PITUITARY NEOPLASMS). Relatively frequent clinical manifestions include visual loss, developmental delay, macrocephaly, and precocious puberty. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2051) Annotation: coord IM with site in hypothalamus (IM) + histol type of neopl (IM) ID#: D007029


Definition: Lower than normal body temperature, especially in warm-blooded animals; in man usually accidental or unintentional. Annotation: do not confuse with HYPOTHERMIA, INDUCED for cooling of organs during surg or for ther; relation to BODY TEMPERATURE: see Manual 23.27+ ID#: D007035


Definition: The clinical syndrome that results from decreased secretion of thyroid hormone from the thyroid gland. It leads to a slowing of metabolic processes and in its most severe form to the accumulation of mucopolysaccharides in the skin, causing a nonpitting edema termed myxedema. Cretinism is the congenital form leading to abnormalities of intellectual and physical development. (Bennett, et al., Cecil Textbook of Medicine, 20th ed) Annotation: ID#: D007037


Definition: Presence of less than the normal amount of hair. (Dorland, 27th ed) Annotation: less than normal amt of hair; do not confuse with HYPERTRICHOSIS, localized or generalized excess hair ID#: D007039


Definition: A reduction in the amount of air entering the pulmonary alveoli. Annotation: respiratory, not environmental ID#: D007040


Definition: An abnormally low volume of blood circulating through the body. It may result in hypovolemic shock (see SHOCK). Annotation: ID#: D020896

Hypoxia, Brain

Definition: A reduction in brain oxygen supply. Severe hypoxia is referred to as anoxia, and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives. (From Adams et al., Principles of Neurology, 6th ed, pp1109-11) Annotation: do not confuse with BRAIN ISCHEMIA, a reduced blood supply ID#: D002534

Hypoxia-Ischemia, Brain

Definition: A disorder characterized by a reduction in oxygen supply (HYPOXIA) combined with reduced blood flow (ISCHEMIA) to the brain. This condition may result from a localized obstruction of a cerebral artery or from systemic hypoperfusion. Prolonged hypoxia-ischemia is associated with ISCHEMIC ATTACK, TRANSIENT; BRAIN INFARCTION; BRAIN EDEMA; COMA; and other conditions. Annotation: ID#: D020925