Category: H

  • Hydrate

    To give water to someone so as to re-establish or maintain fluid balance. A crystalline substance formed by water combining with various compounds.  

  • Hydrarthrosis

    Swelling caused by excess synovial liquid at a joint. Swelling of a joint because of excess synovial fluid; it most often affects the knee and usually indicates inflammation (colloquially called water on the knee). Swelling at a joint caused by excessive synovial fluid. The condition usually involves the knees and may be recurrent. Often no…

  • Hydramnios

    An unusually large amount of amniotic fluid surrounding the fetus. An excessive amount of amniotic fluid surrounding the fetus. This condition occurs in the middle or late stages of pregnancy and is usually harmless. In most cases, the uterus swells to a size only slightly larger than normal and the woman experiences either no symptoms…

  • Hydralazine

    A drug that lowers blood pressure. People usually receive it in combination with other drugs that increase the output of urine. Drug that dilates blood vessels and is used, often in combination with a diuretic, in the treatment of hypertension and congestive heart failure. Adverse effects include headache, rapid heart rate, and gastrointestinal disturbances. It…

  • Hydraemia

    An excess of water in the blood.  

  • Hydatid mole

    An abnormal pregnancy from a pathologic ovum, resulting in a mass of cysts shaped like a bunch of grapes. Abnormality occurring in pregnancy during which portions of the chorion degenerate, forming grapelike masses throughout the placenta, causing death of the embryo and sometimes leading to a malignancy in the uterus. It occurs in about 1…

  • Hydatid disease

    An infection, usually in the lungs or liver, caused by expanding hydatid cysts that destroy the tissues of the infected organ. A rare, potentially fatal disease in humans caused by infection with the larval stage of a microscopic tapeworm found in foxes, coyotes, dogs (especially sheep dogs), and cats. Hydatid disease is also referred to…

  • Hydatid cyst

    The larval form of the tapeworms of the genus Echinococcus. A cyst formed by the growth of the larval form of Echinococcus granulosus, usually in the liver.  

  • Hydatid

    Any cyst-like structure. Cyst-like, usually fluid-filled structure especially that which forms around the dog tapeworm Echinococcus granulosus. A bladderlike cyst formed in various human tissues following the growth of the larval stage of an Echinococcus tapeworm. E. granulosus produces a single large fluid-filled cyst, called a unilocular hydatid, which gives rise internally to smaller daughter…

  • Hyaluronic acid

    A substance which binds connective tissue and is found in the eyes. Chemical present in the vitreous humor of the eye, in movable joints, and certain other tissues; it is a cementing and protective substance, forming a gel in intercellular spaces. An acid mucopolysaccharide that acts as the binding and protective agent of the ground…