water deprivation test
(WAH-ter DEH-prih-VAY-shun …)
A test to measure how much urine is made and how concentrated it becomes when no water is given to a patient for a certain amount of time. This test is used to see how well the kidneys work and to help diagnose diabetes insipidus (a condition in which a person is very thirsty and makes large amounts of urine). Also called fluid deprivation test.