Medical terms - Letter H (page 9) | MedicalVocabulary.org

Heterozygous

Possessing two different forms of a particular gene, one inherited from each parent. A person who is heterozygous is called a heterozygote or a gene carrier. Heterozygous is in contrast to homozygous, the possession of…
HEV

Hepatitis E virus
Hex-A deficiency

See: Tay-Sachs disease
Hexadactyly

The presence of an extra digit, a sixth finger or toe, which is a very common congenital malformation (birth defect). This condition is called hexadactyly. The word hexadactyly literally means six digits. In medical…
Hexalen

Brand name of altretamine. For more information, see: altretamine
Hexenmilch

See: Witch's milk
Hexosaminidase A

An enzyme which, when deficient, causes Tay-Sachs disease, a progressive fatal neurologic disorder concentrated in people of European Jewish (Ashkenazi) descent. See: Tay-Sachs disease
Hexosaminidase A deficiency

See: Tay-Sachs disease
Hg

Symbol for the metallic element mercury. The abbreviation 'mm Hg' means millimeters of mercury, the height of a column of mercury, as in a blood pressure reading. Mercury is poisonous to people. See Mercury poisoning.
HGD

The gene encoding an enzyme called homogentisate 1,2-dioxygenase (also known as homogentisate oxidase). HGD is located on chromosome 3 in region 3q21-q23. Homogentisate oxidase is active chiefly in the liver and…
HHDN

The abbreviation for the scientific name of aldrin. (The scientific name for aldrin [1,2,3,4,10,10-hexachloro-1,4,4á,5,8,8á-hexahydro-1,4-endo,exo-5,8-dimethanonaphthalene] is not easy to recite or recall.) See: Aldrin…
HHS

Acronym for the U.S. Department of Health and Human Services. Also known as DHHS. The U.S. Department of Health and Human Services has two types of operating divisions: the Human Services and the Public Health Service…
HHT

Abbreviation for the disease called hereditary hemorrhagic telangiectasia. See: Hereditary hemorrhagic telangiectasia
HHV-1

Human herpesvirus 1. A herpes virus that causes cold sores and fever blisters in and around the mouth. Here is a depiction of a typical fever blister caused by HHV-1: NTER> In rare cases, as when the immune system is…
HHV-2

Human herpesvirus 2, a virus that causes genital herpes, which is characterized by sores in the area of the genitalia. Genital herpes is a sexually transmitted disease (STD). This virus, like human herpesvirus 1, can…
HHV-3

Human herpesvirus 3. See herpes zoster.
HHV-4

Human herpesvirus 4. See Epstein-Barr virus.
HHV-5

Human herpesvirus 5. See cytomegalovirus.
HHV-6

Human herpesvirus 6
HHV-7

Human herpesvirus 7
HHV-8

Human herpesvirus 8, a herpesvirus that contributes to the development of Kaposi sarcoma, an otherwise rare form of cancer sometimes seen in AIDS patients, and to some B-cell lymphomas. The predominant route of HHV-8…
Hiatal

Pertaining to an hiatus, an opening. An hiatal hernia occurs when a part of the stomach protrudes through the diaphragm at the opening where the esophagus normally passes through the diaphragm. 'Hiatus' in Latin means…
Hiatal hernia

Hiatal hernia: An anatomical abnormality in which part of the stomach protrudes up through the diaphragm into the chest. NTER> Normally, the esophagus passes down through the chest, crosses the diaphragm, enters the…
Hiatus

An opening, as in the diaphragm. When there is an unusually wide opening in the diaphragm, there can be a hiatus (or hiatal) hernia. In Latin an hiatus is 'an opening, gaping mouth, or chasm.' It is derived from the…
Hiatus hernia

Tal hernia): An anatomical abnormality in which part of the stomach protrudes up through the diaphragm into the chest. NTER> Normally, the esophagus passes down through the chest, crosses the diaphragm, enters the…
HIB

This immunization is designed to prevent diseases caused by Haemophilus influenzae type B (HIB), a bacteria responsible for a range of serious "invasive" diseases including meningitis with potential brain damage and…
HIB immunization

This immunization is designed to prevent diseases caused by Haemophilus influenzae type B (HIB), a bacteria responsible for a range of serious 'invasive' diseases including meningitis with potential brain damage and…
Hibernation reaction

See: SAD
Hiccough

A hiccough is an extraordinary type of breathing movement involving a sudden intake of air (inspiration) due to an involuntary contraction of the diaphragm accompanied by closure of the vocal apparatus (glottis) of the…
Hiccup

A hiccup is an extraordinary type of respiratory movement involving a sudden inspiration (intake of air) due to an involuntary contraction of the diaphragm accompanied by closure of the glottis (the vocal apparatus of…
Hidradenitis suppurativa

This is an illness characterized by multiple abscesses that form under the arm pits and in the groin area
Hidrosis

Sweating, the production of perspiration. Hidrosis is the Greek word for sweating
Hidrotic

Pertaining to hidrosis, sweating, the production of perspiration. Hidrotic ectodermal dysplasia is the form of this hereditary disease in which the patient can sweat, as opposed to anhidrotic ectodermal dysplasia in…
High altitude

Altitude sickness occurs at high altitude. So what is high altitude? Altitude is defined on the following scale: > >High altitude: 8,000 - 12,000 feet (2,438 - 3,658 meters); >Very high altitude: 12,000 - 18,000 feet…
High altitude pulmonary edema

High altitude pulmonary edema: Known for short as HAPE, the accumulation in the lungs of extravascular fluid (fluid outside of blood vessels) at high altitude, a consequence of rapid altitude ascent, especially when…
High blood pressure

High blood pressure: Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above…
High blood sugar

An elevated level of the sugar glucose in the blood. Also called hyperglycemia. High blood sugar is a finding in a number of conditions, most notably diabetes mellitus. Elevated blood glucose leads to spillage of…
High protein diet

A high protein diet is a type of weight loss plan that emphasizes consumption of high-protein-containing foods. There are many different kinds of high protein diets. Many high protein diets may be risky for overall…
High-grade lymphoma

A lymphoma that grows and spreads quickly but has a better response to anticancer drugs than that seen with low-grade lymphomas. High-grade lymphomas include large cell, immunoblastic, lymphoblastic, and small…
Hip bursitis

Hip bursitis: A bursa is a fluid-filled sac that functions as a gliding surface to reduce friction between moving tissues of the body. There are two major bursae of the hip. Bursitis is usually not infectious, but the…
Hip dislocation, congenital

The abnormal formation of the hip joint in which the ball at the top of the thighbone (the femoral head) is not stable within the socket (the acetabulum). The ligaments of the hip joint may also be loose and stretched…
Hip fracture

Broken bone in the hip, a key health problem among the elderly, usually due to a fall or other kind of trauma involving direct impact to the hip bone which has been weakened by osteoporosis. The part of the hip most…
Hip pain

Hip pain is the sensation of discomfort in or around the hip joint, where the upper end (head) of the thigh bone (femur) fits into the socket of the hip bone. Hip pain has a number of causes, most of which are related…
Hip pointer

Sportstalk for an iliac crest contusion (a bruise of the upper edge of the ilium, one of the hip bones).
Hip replacement, total

Hip replacement, total: Surgery in which the diseased ball and socket of the hip joint are completely removed and replaced with artificial materials. A metal ball with a stem (a prosthesis) is inserted into the femur…
Hip, developmental dislocation of the (DDH)

The abnormal formation of the hip joint in which the ball at the top of the thighbone (the femoral head) is not stable within the socket (the acetabulum). The ligaments of the hip joint may also be loose and stretched…
HIPAA

Acronym that stands for the Health Insurance Portability and Accountability Act, a US law designed to provide privacy standards to protect patients' medical records and other health information provided to health plans…
Hippocampus

An area buried deep in the forebrain that helps regulate emotion and memory. Functionally, the hippocampus is part of the olfactory cortex, that part of the cerebral cortex essential to the sense of smell. Certain…
Hippocrates

Rally credited with turning away from divine notions of medicine and using observation of the body as a basis for medical knowledge. Prayers and sacrifices to the gods did not hold a central place in his theories, but…
Hippocratic Oath

One of the oldest binding documents in history, the Oath written by Hippocrates is still held sacred by physicians: to treat the ill to the best of one's ability, to preserve a patient's privacy, to teach the secrets of…