Medical terms - Letter H (page 8) | MedicalVocabulary.org

Hereditary prostate cancer

Prostate cancer: A genetic form of prostate cancer. The risk of prostate cancer is clearly genetic. Men with a father or brother with prostate cancer are twice as likely to develop prostate cancer as men with no…
Hereditary sensory and autonomic neuropathy III

A degenerative disorder of nerves with progressive spasticity of the legs. Abbreviated as AD-HSP. Spasticity is a state of increased muscle tone. Paraplegia refers to the legs (quadriplegia refers to both the arms and…
Hereditary spastic paraplegia, autosomal dominant

A degenerative disorder of nerves with progressive spasticity of the legs. Abbreviated as AD-HSP. Spasticity is a state of increased muscle tone. Paraplegia refers to the legs (quadriplegia refers to both the arms and…
Hereditary spherocytosis

A genetic disorder of the red blood cell membrane clinically characterized by anemia, jaundice (yellowing) and splenomegaly (enlargement of the spleen). In HS the red cells are smaller, rounder, and more fragile than…
Heredity

Genetic transmission from parent to child.
Heredofamilial tremor

See: Essential tremor
Hereford genome

See: Bovine genome
Heritability

The degree to which something is inherited.
Heritable

Capable of being transmitted from parent to child.
Heritable connective tissue disease

A disorder due to mutation of a gene responsible for connective tissue, the material that gives tissues form and strength. These mutations may change the structure and development of skin, bones, joints, heart, blood…
Hermansky-Pudlak syndrome

Abbreviated HPS. A genetic disorder characterized by albinism (with lack of pigment in the skin or eye), bruising and prolonged bleeding (due to defective blood platelets), and fibrosis of the lungs. There is…
Hernia

Hernia: A general term referring to a protrusion of a tissue through the wall of the cavity in which it is normally contained. More specifically, a hernia often refers to an opening or weakness in the muscular structure…
Hernia repair

Also called a herniorrhaphy, a surgical repair of a hernia. Hernia repair may be done under local or general anesthesia using a conventional incision or a laparoscope. The alternative term 'herniorrhaphy' comes from…
Hernia, diaphragmatic

Hernia: Passage of a loop of bowel through the diaphragm muscle. This type of hernia occurs as the bowel from the abdomen 'herniates' upward through the diaphragm into the chest (thoracic) cavity. Diaphragmatic hernias…
Hernia, hiatus

Protrusion of the stomach up into the opening normally occupied by the esophagus in the diaphragm, the great dome of muscle that separates the thoracic (chest) cavity from the abdomen. NTER> Normally, the esophagus…
Hernia, Velpeau

Hernia, Velpeau: A Velpeau hernia is a femoral hernia in front of the femoral blood vessels in the groin. (A hernia ('rupture') is a protrusion of tissue through the wall of a cavity in which it is normally contained.)…
Herniated disc

Herniated disc: Rupturing of the tissue that separates the vertebral bones of the spinal column. The center of the disc, which is called the nucleus, is soft, springy and receives the shock of standing, walking…
Herniation

Abnormal protrusion of tissue through an opening. For example, a intervertebral disk (one situated between the vertebral bodies) can protrude and impinge on a nerve root.
Herniorrhaphy

The surgical repair of a hernia. Herniorrhaphy may be done under local or general anesthesia using a conventional incision or a laparoscope. The term 'herniorrhaphy' comes from hernio-, referring to a hernia + the Greek…
Heroin

Semisynthetic drug derived from morphine. Discovered in 1874, it was introduced commercially in 1898 by the Bayer company in Germany. The name heroin was coined from the German heroisch meaning heroic, strong. Heroin is…
Heroin addiction

Physical addiction to heroin, often with concurrent use of other opiates when heroin itself is not available. Treatment is by withdrawal, either gradual or sudden. Medication may be used to ease the physical effects of…
Herpes

A family of viruses. Herpes also refers to infection with one of the human herpesviruses, especially herpes simplex types 1 and 2. Herpes simplex type 1, also known as human herpesvirus 1 (HHV-1), causes cold sores and…
Herpes simplex type 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 herpes simplex 1: NTER> In rare cases, as when someone's immune system is…
Herpes simplex type 2

A herpes virus that causes genital herpes, which is characterized by sores in the genital area. Genital herpes is a sexually transmitted disease (STD). This virus, like herpes simplex type 1, can also cause infection of…
Herpes zoster

Also called shingles, zona, and zoster. The culprit is the varicella-zoster virus. Primary infection with this virus causes chickenpox (varicella). At this time the virus infects nerves (namely, the dorsal root ganglia)…
Herpes, febrile

A small sore situated on the face or in the mouth that causes pain, burning, or itching before bursting and crusting over. The favorite locations are on the lips (the labia), chin or cheeks and in the nostrils. Less…
Herpes, genital

See: Genital herpes
Herpes, labial

A small sore situated on the face or in the mouth that causes pain, burning, or itching before bursting and crusting over. The favorite locations are on the lips (the labia), chin or cheeks and in the nostrils. Less…
Herpesvirus

One of a family of double-stranded DNA viruses that cause common infections in humans. These include: herpes, CMV, chickenpox, shingles, mono, measles, and Kaposi sarcoma. The herpesviruses may live latently in a person…
Herpetiform virus

A virus with the characteristic shape and behavior of a virus in the herpes family. Not all members of the herpes virus family have been identified. Some herpetiform viruses may eventually be called herpes viruses…
Hershey-Chase experiment

An extraordinarily important experiment in 1952 that helped to convince the world that DNA was the genetic material. Alfred Hershey (1908-1997) and his assistant Martha Chase (1923-2003) at the Cold Spring Harbor…
Hetero-

Chromosomal material that is darkly staining and tightly coiled throughout the cell cycle and that is, for the most part, genetically inactive. There are two types of heterochromatin: constitutive heterochromatin and…
Heterochromatin

Chromosomal material that is darkly staining and tightly coiled throughout the cell cycle and that is, for the most part, genetically inactive. There are two types of heterochromatin: constitutive heterochromatin and…
Heterochromatin, constitutive

Heterochromatin that is fixed and irreversible. Regions of constitutive heterochromatin are located at very specific spots in the genome (on chromosomes 1, 9, 16 and the Y chromosome, the tiny short arms of chromosomes…
Heterochromatin, facultative

Heterochromatin that need not always be heterochromatic but which has the faculty to return to the normal euchromatic state. The inactive X chromosome is made up of facultative heterochromatin. When a woman transmits…
Heterochromia

Different colors
Heterochromia iridis

A difference of color between the iris of one eye and the other. (A person with one brown and one blue eye has heterochromia iridis.) Also, a difference in color within an iris (sectoral heterochromia iridis).
Heteroclite

Deviating from the ordinary; irregular or abnormal; anomalous. As, for example, retroviruses represent a heteroclite field of virology. From the Greek hetero- (different) + klinein (to lean, inflect)
Heteroerotic

Having to do with sexual excitement toward the opposite sex. By contrast with alloerotic
Heterokaryon

A cell with two separate nuclei formed by the experimental fusion of two genetically different cells. (Heterokaryons, for example, composed of nuclei from Hurler syndrome and Hunter syndrome, both diseases of…
Heteromorphism

Something different in form. Chromosome heteromorphisms are normal variations in the appearance of chromosomes
Heterophyes

The replacement of normal tissue of the body by abnormal tissue or by malpositioned normal tissue, a tissue growing in the wrong place. Progressive osseous heteroplasia is a disorder in which bone develops in areas…
Heteroplasia

The replacement of normal tissue of the body by abnormal tissue or by malpositioned normal tissue, a tissue growing in the wrong place. Progressive osseous heteroplasia is a disorder in which bone develops in areas…
Heteroploid

A different chromosome number than the normal number of chromosomes
Heterosexual

A person sexually attracted to persons of the opposite sex. Or a person who has sexual relations with the opposite sex. Colloquially known as 'straight.' The term 'heterosexual' can also be an adjective.
Heterosexuality

Sexuality directed toward someone of the opposite sex
Heterotaxy

The abnormal placement of organs due to failure to establish the normal left-right patterning during embryonic development. The morbidity (disease) and mortality (death) from heterotaxy are caused by congenital defects…
Heterotopic

In the wrong place, in an abnormal place, misplaced. From the Greek roots 'hetero-' meaning 'other' + 'topos' meaning 'place' = other place. For example, heterotopic bone formation is the formation of bone where it is…
Heterotrisomy

Trisomy of different chromosomes. The occurrence of two children in the same family, one with trisomy 18 and the other with trisomy 21, is an instance of heterotrisomy. See also: Homotrisomy.
Heterozygote

A person possessing two different forms of a particular gene, one inherited from each parent. A heterozygote is also called a carrier. For example, a woman who is a heterozygote for cystic fibrosis (CF) carries the CF…