Central diabetes insipidus occurs when the body has a lower than normal amount of antidiuretic hormone (ADH). ADH is also called vasopressin. ADH is produced in a part of the brain called the hypothalamus. It is then stored and released from the pituitary gland. This is a small gland at the base of the brain.
ADH controls the amount of water excreted in urine. Without ADH, the kidneys do not work properly to keep enough water in the body. The result is a rapid loss of water from the body in the form of dilute urine. This results in the need to drink large amounts of water due to extreme thirst and to make up for excessive water loss in the urine (as much as 4 gallons a day).
The reduced level of ADH may be caused by damage to the hypothalamus or pituitary gland. This damage may be due to surgery, infection, inflammation, tumor, or injury to the brain.
Sometimes the cause is unknown. In rare cases, central diabetes insipidus is caused by a genetic problem.