Category: H

An operation to repair a joint which replaces one of its surfaces with an artificial substance, often metal.  

A state of partial blindness in which someone has only half the usual field of vision in each eye. Blindness to one half of the visual field in one or both eyes; also: hemianopsia. Loss of vision in half of the normal visual field (right or left, top or bottom). Blindness in half of the…

A usually congenital condition in which someone is able to see better in bad light than in ordinary daylight. Abnormal condition in which bright light causes a blurring of vision; a side effect of some anticonvulsant drugs; also called day blindness. Diminished vision in bright light. The term formerly was erroneously applied to night blindness…

A type of white blood cell that stimulates the production of cells that destroy antigens.  

A person who helps someone to do something, especially without payment.  

A finding which states that twins should occur naturally once in 90 live births, triplets once in 8,100 live births, quadruplets once in 729, 000 live births, and quintuplets once in 65, 610, 000 live births. A law stating that twins occur once in 80 pregnancies, triplets once in 6400 (802) pregnancies, quadruplets once in…

A very light gas used in combination with oxygen, especially to relieve asthma or sickness caused by decompression. The lightest gas known, with the exception of hydrogen. This property renders it of value in anaesthesia, as its addition to the anaesthetic means that it can be inhaled with less effort by the patient. Thus it…

A skin graft to cover an ulcer to aid healing.  

An emergency treatment for choking, in which a strong upward push beneath the breastbone of a patient clasped from behind forces the blockage out of the windpipe. The Heimlich maneuver is a first-aid technique used to assist choking victims. Its purpose is to dislodge the obstructing material and clear the airway. To perform the Heimlich…

The bone forming the heel, beneath the talus.