In diseases of the HEART, this is used to indicate a condition in which, as the result of valvular disease, the blood does not entirely pass on from the atria of the heart to the ventricles, or from the ventricles into the arteries. The defective valve is said to be incompetent, and a certain amount of blood leaks past it, or regurgitates back, into the cavity from which it has been driven. (See HEART, DISEASES OF.)

The return to the mouth of food already swallowed and present in the oesophagus or stomach (REFLUX).