Diabetes insipius (DI) is a condition characterized by excretion of large amounts of severely diluted urine, which cannot be reduced when fluid intake is reduced. It denotes inability of the kidney to concentrate urine. DI is caused by a deficiency of antidiuretic hormone (ADH), also known as vasopressin, due to the destruction of the back or "posterior" part of the pituitary gland where vasopressin is normally released from, or by an insensitivity of the kidneys to that hormone. It can also be induced iatrogenically by various drugs.