Category: Hy-Hz

A thin membrane that may completely or partially cover the vaginal opening before first sexual intercourse but that usually disappears before puberty.

The science of preventive medicine and the preservation of health. Also commonly used as a euphemism for cleanliness and proper sanitation.

A drug that inhibits the synthesis of DNA and so is classified as an antimetabolite. Hydroxyurea is used to treat a number of diseases, including chronic myeloid leukemia (CML), polycythemia vera, carcinoma of the head and neck, ovary, and cervix, melanoma, and sickle cell disease. Hydroxyurea is taken orally.

A major component and an essential ingredient of normal bone and teeth. Hydroxyapatite makes up bone mineral and the matrix of teeth. It is hydroxyapatite that gives bones and teeth their rigidity. Hydroxyapatite molecules can group together (crystalize) to form microscopic clumps. If these tiny crystals of hydroxyapatite are deposited by mistake in or around joints, they may cause…

1. Literally, an irrational fear of water, to drink or to swim in. Someone who is scared of the water is hydrophobic. 2. A term once commonly used for rabies because in the later stages of that disease, the animal (or person) has difficulty swallowing and so fears a drink of water. From hydro-, water + -phobia, fear.

Also known as hydrocephalus, this is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under increased pressure and can compress and damage the brain. Hydrocephalus can arise before birth or any time afterward. It may be due to many causes including a birth defect, hemorrhage into the brain, infection, meningitis, tumor, or head injury.…

What is termed “hydrocephalus ex-vacuo” occurs when there is damage to the brain caused by stroke or injury, and there may be an actual shrinkage of brain substance. Although there is more CSF than usual, the CSF pressure itself is normal in hydrocephalus ex-vacuo. Hydrocephalus is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid…

A tumor that forms in the uterus as a mass of cysts resembling a bunch of grapes. Hydatidiform moles occur during the childbearing years, and they do not spread outside the uterus. However, a malignancy called choriocarcinoma may start from a hydatidiform mole. In its early stages, a hydatidiform mole may look like a normal pregnancy. Diagnosis is based on a history of lack…

A respiratory disease of the newborn, especially the premature infant, in which a membrane composed of proteins and dead cells lines the alveoli (the tiny air sacs in the lung), making gas exchange difficult or impossible. The word “hyaline” comes from the Greek word “hyalos” meaning “glass or transparent stone such as crystal.” The membrane in hyaline membrane disease looks glassy.…