Medical terms - Letter H (page 11) | MedicalVocabulary.org

Hobbit

Nickname for the Flores man (Homo floresiensis). Derived from the fictional race from J. R. R. Tolkien's Middle-earth universe which first appears in the book The Hobbit
Hodgkin disease

British crystallographer and Nobel Prize winner (1910-1994). Dorothy Crowfoot, as she was born, was educated at Somerville College, Oxford. After a brief period as a postgraduate student at Cambridge University, she…
Hodgkin, Dorothy

British crystallographer and Nobel Prize winner (1910-1994). Dorothy Crowfoot, as she was born, was educated at Somerville College, Oxford. After a brief period as a postgraduate student at Cambridge University, she…
Hogwarts headache

Headache: A generalized headache from spending many hours reading an unusually long volume such as one of J.K. Rowling's Harry Potter books. The pain resolves one to two days after the patient finishes the book. The…
Holandric inheritance

Inheritance of genes on the Y chromosome. Since only males normally have a Y chromosome, Y-linked genes can only be transmitted from father to son. It has often been said that little is known about specific genes that…
Hole, macular

A hole in the macula, the tiny oval area made up of millions of nerve cells located at the center of the retina responsible for sharp, central vision. The eye contains a jelly-like substance called the vitreous…
Holmes, Oliver Wendell, Sr.

(1809-1894). Celebrated American physician and professor of medicine (anatomy and physiology) at Harvard, and of novels, verse, and essays, including medical essays. In one of them, Holmes wrote: 'If every drug from the…
Holoprosencephaly

A relatively common birth defect of the brain, which often also affects facial features, causing closely spaced eyes, small head size, and sometimes clefts of the lip and roof of the mouth. Not all individuals with…
Holt-Oram syndrome

A genetic syndrome characterized by the combination of heart disease and malformations of the upper limb. The heart defect is usually an atrial septal defect (ASD) and, less often, a ventricular septal defect (VSD)…
Holter monitor

A type of portable heart monitor. The Holter monitor is a small portable electrocardiogram (ECG). The device is worn in a pouch around the neck or waist. It keeps a record of the heart rhythm, typically over a 24-hour…
Homeobox gene

A gene containing a short DNA sequence of about 180 base pairs referred to as a homeobox. Homeobox genes encode proteins that bind and regulate the expression of DNA in multicellular organisms. Homeoboxes are present in…
Homeopath

A person who practices homeopathy.
Homeopathic

Pertaining to homeopathy
Homeopathic medicine

See: Homeopathy
Homeopathy

A system of therapy based on the concept that disease can be treated with drugs (in minute doses) thought capable of producing the same symptoms in healthy people as the disease itself. Homeopathy was invented by the…
Homeostasis

A property of cells, tissues, and organisms that allows the maintenance and regulation of the stability and constancy needed to function properly. Homeostasis is a healthy state that is maintained by the constant…
Homeotherm

A homeotherm is a warm-blooded animal (such as homo sapiens). Another term for us warm-blooded creatures is endotherm. Those of us who are homeotherms or endotherms are as opposed to a poikilotherm (an organism such as…
Homicide

1. The killing of a person. 2. Strictly speaking, the killing of a man. femicide. From the Latin meaning murderer, from homo, man + caedere, to kill
Homo erectus

A primate believed to have been an extinct ancestor of modern humans being (Homo sapiens). Known to have been tall (average 1.78 m or 5 feet, 10 inches), erect stature, smaller brain (about 75% the size of Homo…
Homo floresiensis

A human-like species who lived until 18,000 years ago in the company of giant Komodo lizards and now-extinct pygmy elephants on the isolated island of Flores in Indonesia. Homo floresiensis was only one meter (3 feet)…
Homo sapiens

The primate species of mammal to which modern humans belong. Homo sapiens is Latin for knowing man or wise man
Homo-

An amino acid produced by the body, usually as a byproduct of consuming meat. Homocysteine is made from another amino acid, methionine, and then in turn is converted into other amino acids. Elevated levels of…
Homocysteine

Homocysteine: An amino acid produced by the body, usually as a byproduct of consuming meat. Homocysteine is made from another amino acid, methionine, and then in turn is converted into other amino acids. Elevated levels…
Homocystinuria

A genetic disease due to an enzyme deficiency. Among other events, there is a buildup of the amino acid homocystine. Progressive mental retardation is common in untreated cases. The finding of vascular disease and…
Homogentisate 1,2-dioxygenase

The enzyme encoded in the HGD gene. Mutation of HGD causes the genetic disease alkaptonuria. Homogentisate 1,2-dioxygenase is also called homogentisate oxidase
Homogentisate oxidase

The enzyme encoded in the HGD gene. Mutation of HGD causes the genetic disease alkaptonuria. Homogentisate oxidase is also called Homogentisate 1,2-dioxygenase
Homogentisic acid oxidase deficiency

Alkaptonuria
Homograft

See: Allograft
Homolog (homologue)

One chromosome of a pair.
Homologies

Similarities in DNA or protein sequences between individuals or between species
Homologous

The relationship between two chromosomes that are paired and so are homologs of each other.
Homologous chromosomes

A pair of chromosomes containing the same gene sequences, each derived from one parent
Homosexual

A person sexually attracted to persons of the same sex. Homosexuals include males (gays) and females (lesbians). The term 'homosexual' can also be an adjective.
Homosexuality

Sexuality directed toward someone of the same sex
Homosexuality 1

Trisomy of the same chromosome. The occurrence of two children in the same family with trisomy 21 is an instance of homotrisomy. See also: Heterotrisomy.
Homotrisomy

Trisomy of the same chromosome. The occurrence of two children in the same family with trisomy 21 is an instance of homotrisomy. See also: Heterotrisomy.
Homozygosity

The state of possessing two identical forms of a particular gene, one inherited from each parent. For example, a girl who is homozygous for cystic fibrosis (CF) received the CF gene from both of her parents and…
Homozygote

A person who has two identical forms of a particular gene, one inherited from each parent. For example, a girl who is a homozygote for cystic fibrosis (CF) received the CF gene from both of her parents and therefore has…
Homozygous

Possessing two identical forms of a particular gene, one inherited from each parent
Honey bee allergy

Allergic reactions to stings of the honey bee (Apis mellifera). These reactions can include dizziness, itching, welts, massive swelling, trouble breathing, low blood pressure, shock, and even death. See: First Aid For…
Honey bee genome

The genetic complement of the honey bee (Apis mellifera). Its genome is relatively small -- about one-tenth the size of the human genome -- and contains about 300 million DNA base pairs. Sequencing of the bee genome…
Hong Kong flu

A pandemic of influenza A (H3N2) in 1968-69. This virus was first detected in Hong Kong in early 1968 and spread to the United States later that year. where it caused about 34,000 deaths, making it the mildest pandemic…
Hong Kong influenza

See: Hong Kong flu
Hookworm

An intestinal parasite that usually causes diarrhea or cramps. Heavy infestation with hookworm can be serious for newborns, children, pregnant women, and persons who are malnourished. Hookworm infections occur mainly in…
Horace Albert Barker

See: Barker, Horace Albert
Horace Barker

See: Barker, Horace Albert
Horizontal

A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by specialized glands such as the thyroid gland. Hormones are essential for every…
Hormone

A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by specialized glands such as the thyroid gland. Hormones are essential for every…
Hormone replacement therapy (HRT)

The combination therapy of estrogen plus progestogen, termed hormone replacement therapy (HRT). Estrogen replacement therapy (ERT) is used to treat menopause. It reduces or stops the short-term changes of menopause such…
Hormone therapy

Hormone therapy: A form of treatment that takes advantage of the fact that certain cancers depend on hormones to grow. Hormone therapy may include giving hormones to the patient or decreasing the level of hormones in…