Medical terms - Letter H (page 10) | MedicalVocabulary.org

Hippophobia

An abnormal and persistent fear of horses. Sufferers of this fear experience undue anxiety even when a horse is known to be gentle and well trained. They usually avoid horses entirely rather than risk being kicked…
Hirschsprung disease

Hirschsprung disease: A congenital abnormality (birth defect) of the bowel in which there is absence of the ganglia (nerves) in the wall of the bowel. Nerves are missing starting at the anus and extending a variable…
Hirsutism

Having an overabundance of hair. A person with hirsutism is said to be hirsute (pronounced hir-suit). Hirsutism is the Roman way of saying hairy. It comes from the Latin 'hirsutus' meaning bristly or rude.
Hirudin

An anticoagulant ('bloodthinner'). Hirudin is the active principle in the salivary secretion of leeches. The name hirudin is from Hirudo medicinalis, the name of the medicinal leech. In 1884 John Haycraft in Strasbourg…
Hirudotherapy

The use of leeches for medical therapy. Sometimes referred to as the 'treatment that sucks.' From hirudin, the active principle in the salivary secretion of leeches that acts as a potent anticoagulant (bloodthinner).
His

Histidine. See also: Amino acid symbols
His disease

This is a parasite (louse-borne) disease that was first recognized in the trenches of World War I and so was called trench fever. It is estimated to have affected more than a million people in Russia and on the war…
His-Werner disease

This is a parasite (louse-borne) disease that was first recognized in the trenches of World War I and so was called trench fever. It is estimated to have affected more than a million people in Russia and on the war…
Histamine

Substance that plays a major role in many allergic reactions. Histamine dilates blood vessels and makes the vessel walls abnormally permeable.
Histamine cephalalgia

A distinctive syndrome of headaches, also known as cluster headache or migrainous neuralgia. The common pattern of cluster headache is termed 'episodic' and is characterized by 1-3 short attacks of pain each day around…
Histidine

An amino acid, one of the 20 building blocks of protein. An essential amino acid, histidine is present in many proteins. Histidine is elevated in the blood and urine in a genetic condition called histidinemia…
Histiocyte

A type of white blood cell, also called a macrophage, that is created by the bone marrow. They usually stay in place, but when histiocytes are stimulated by infection or inflammation they become active, attacking…
Histiocytic necrotizing lymphadenitis

A disorder, also called Kikuchi disease, that typically causes 'swollen glands' in the neck (cervical lymphadeniopathy) together with fever or flu-like symptoms. Laboratory test abnormalities include elevated…
Histiocytosis

A rare but potentially deadly disorder with similarities to cancer, in which histiocytes start to multiply and attack the person's own tissues or organs. The result can be tissue damage, pain, development of tumor-like…
Histiocytosis X

Now called Langerhans cell histiocytosis. This disease is subclassified into eosinophilic granuloma, Letterer Siwe disease, and Hand-Schuller-Christian disease
Histiocytosis, Hand-Schuller-Christian

A disease in which histiocytes start to multiply and attack the tissues or organs of the patient. The disease usually affects children age 2 to 5, less often older children and adults. The most frequent sites of bony…
Histiocytosis, Langerhans cell

Histiocytosis in which the active histiocytes normally occur in the skin. See histiocytosis.
Histiocytosis, Letterer Siwe

A severe disease in which histiocytes start to multiply and attack the tissues or organs of the patient starting in infancy with a scaly, sometimes itchy rash on the scalp, ears, abdomen, and creases of the neck and…
Histiocytosis, lipid

A form of histiocytosis that affects lipid (fat) storage. Also known as Niemann- Pick disease, Erdheim-Chester disease
Histiocytosis, malignant

Histiocytosis in which the histiocytes actually become cancerous. Treatment is by radiation and chemotherapy, and in some cases bone-marrow transplantation. See also histiocytosis.
Histiocytosis, sinus

A variant of histiocytosis in which the lymph nodes are the main site of histiocyte proliferation. The sinuses become filled with and distended by masses of histiocytes. See also histiocytosis.
Histo

Popular name for the fungus histoplasma. Also medical school slang for histology
Histo spot

A small circular punched-out spot in the retina at a site where spores of the fungus histoplasma (histo) seeded in the eye. Histo spots may be multiple, found in both eyes, and scattered throughout the retina. Histo…
Histo-

Literally, tissue compatibility. With full histocompatibility between a donor and recipient, tissue can be transplanted without being seen as foreign and being attacked by the immune system of the recipient.
Histocompatibility

Literally, tissue compatibility. With full histocompatibility between a donor and recipient, tissue can be transplanted without being seen as foreign and being attacked by the immune system of the recipient
Histocompatible

Literally, tissue compatible. If a donor and recipient are histocompatible, a transplant is expected to be easily accepted.
Histology

The study of the form of structures seen under the microscope. Also called microscopic anatomy, as opposed to gross anatomy which involves structures that can be observed with the naked eye. Traditionally, both gross…
Histone

A protein around which DNA coils to form chromatin. Without this protein material, DNA could not organize into chromosomes, and life as we know it would not exist
Histoplasma

See: Histoplasma.
Histoplasma capsulatum

See: Histoplasma
Histoplasmosis

A disease caused by the fungus Histoplasma capsulatum. Most people with histoplasmosis have no symptoms. However, histoplasma can cause acute or chronic lung disease and progressive disseminated histoplasmosis affecting…
History, developmental

An account of how and when a person met developmental milestones, such as walking and talking. For adults, information on social-emotional development may be included. Used primarily in the diagnosis of developmental…
History, family

The family structure and relationships within the family, including information about diseases in family members. The family history is often recorded in a family pedigree (family tree), which uses conventional symbols…
History, medical

See: Medical history
History, social

An account of a patient that puts his illness or behavior in context. It may include aspects of the patient's developmental, family, and medical history, as well as relevant information on life events, social class…
HIV

Acronym for the Human Immunodeficiency Virus, the cause of AIDS (acquired immunodeficiency syndrome). HIV has also been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the…
HIV infection, acute

The body's initial reaction to infection by the HIV virus. Acute HIV infection is a flu-like syndrome that occurs immediately after a person contracts HIV (the human immunodeficiency virus 1, the agent that causes…
HIV infection, primary

The first few months after infection with HIV (the human immunodeficiency virus). During primary HIV infection, seroconversion occurs -- the appearance of detectable antibodies to HIV in the blood. It normally takes…
HIV test

A test for the human immunodeficiency virus, the cause of AIDS. HIV tests are designed to detect antibodies to the HIV virus or the HIV virus itself. The antibody tests are: > >ELISA (enzyme-linked immunosorbent assay)…
Hives

Hives: A raised, itchy area of skin that is usually a sign of an allergic reaction. It can be rounded or flat-topped but is always elevated above the surrounding skin. It reflects circumscribed dermal edema (local…
Hives from pressure

See Pressure urticaria
HLA

The major human histocompatibility system. HLA-typing is done before transplantation to determine the degree of histocompatibility. HLA is an acronym for Human Leukocyte Antigens
HLA-B57

An HLA type that is strongly associated with unusually slow progression of the human immunodeficiency virus (HIV) from the primary infection to AIDS. In other words, HLA-B57 provides some protection against HIV…
HMPS

Hereditary mixed polyposis syndrome
HMPV

Human metapneumovirus
HMS1

Homosexuality 1. An alleged gene for human male homosexuality. See: Gay gene
HNP

Human neutrophil peptide
HNPCC

Hereditary nonpolyposis colon cancer
Hoarding, pathological

Hoarseness is a term referring to abnormal voice changes. Hoarseness may be manifested as a voice that sounds breathy, strained, rough, raspy, or a voice that has higher or lower pitch. There are many causes of…
Hoarseness

Hoarseness: Hoarseness is a term referring to abnormal voice changes. Hoarseness may be manifested as a voice that sounds breathy, strained, rough, raspy, or a voice that has higher or lower pitch. There are many causes…