Central diabetes insipidus is a rare condition that involves extreme thirst and excessive urination.

See also: Diabetes insipidus - nephrogenic

Central diabetes insipidus occurs when the body has too little of the hormone vasopressin.

Vasopressin normally limits the amount of urine the body produces. Normally, the hypothalamus gland in the brain makes vasopressin, and the pituitary gland stores the hormone. Without vasopressin, the kidneys do not work properly. The result is a rapid loss of water from the body in the form of dilute urine. A person with diabetes insipidus drinks large quantities of water, driven by extreme thirst, to make up for the water loss.

The reduced levels of vasopressin associated with central diabetes insipidus may be caused by damage to the hypothalamus or pituitary gland. This damage may be related to surgery, infection, inflammation, tumor, or injury to the head.

Sometimes the cause remains unknown. Very rarely, diabetes insipidus can be caused by a genetic defect.

• Increased amount of urine production
• Excessive thirst
• Confusion and changes in consciousness (if the patient is unable to drink)

A person with central diabetes insipidus produces more than 3 liters of urine a day. Urinalysis will show a low concentration of salt in the urine.

A water restriction test is used to look at how well the kidney works and how much urine is produced. This test is done during a hospital stay. Results are checked every hour. A blood test to check plasma sodium concentration is done every 2 hours. Serum sodium/salt concentration may be high if the condition is untreated.

An MRI of the head may show a problem in or near the pituitary gland.