Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «H»:
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 kidneys. It is needed to break down the amino acids phenylalanine and tyrosine. Pre...
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 and dieldrin....
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 Operating Divisions. The Public Health Service Operating Divisions include th...
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:
In rare cases, as when the immune system is severely compromised, this virus can cause infection of the brain (encephalitis)...
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 cause infection of the brain (encephalitis) if the immune system is severe...
HHV-3: Human herpesvirus 3. See herpes zoster....
HHV-4: Human herpesvirus 4. See Epstein-Barr
HHV-5: Human herpesvirus 5. See
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
The predominant route of HHV-8 transmission is sexual. An additional route is via blood contact among i...
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 an opening....
Hiatal hernia: An anatomical abnormality in which part of the stomach protrudes up through the diaphragm into the chest.
Normally, the esophagus passes down through the chest, crosses the diaphragm, enters the abdomen through a hole in the diaphragm called the esophageal hiatus and joins the stom...
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 verb "hiare" meaning "to gape or yawn." Therefore, a "hiatus" is a gaping...