ADH secretion, inappropriate: The syndrome of inappropriate secretion of antidiuretic hormone (ADH) results in the inability to put out dilute urine, perturbs fluid (and electrolyte) balance, and causes nausea, vomiting, muscle cramps, confusion and convulsions. This syndrome may occur, for example, with oat-cell lung cancer, pancreatic cancer, prostate cancer, and Hodgkin's disease as well as a number of other disorders.

ADH is a hormone released by pituitary gland but made elsewhere (in the hypothalamus). ADH has an antidiuretic action; it suppresses the rate of urine production. ADH is also known as vasopressin.