A
diuretic is any substance that promotes the production of
urine. This includes
forced diuresis. There are several categories of diuretics. All diuretics increase the excretion of
water from bodies, although each class does so in a distinct way. Alternatively, an
antidiuretic such as
vasopressin, or
antidiuretic hormone, is an agent or drug which reduces the excretion of water in urine.