Causes

Diabetes insipidus occurs when your body can't properly balance the body's fluid levels.

Your kidneys filter the fluid portion of your blood to remove waste products. The majority of the fluid is returned to the bloodstream while the waste and a smaller amount of fluid make up urine. Urine is excreted from your body after being temporarily stored in your bladder.

A hormone called anti-diuretic hormone (ADH), or vasopressin, is needed for the fluid that's filtered by the kidneys to go back into the bloodstream. ADH is made in a part of the brain called the hypothalamus and stored in the pituitary gland, a small gland found in the base of the brain. Conditions that cause a deficiency of ADH or block the effect of ADH result in production of excess urine.

If you have diabetes insipidus, your body can't properly balance fluid levels. The cause depends on the type of diabetes insipidus you have. Types include:

• Central diabetes insipidus. Damage to the pituitary gland or hypothalamus from surgery, a tumor, head injury or illness can cause central diabetes insipidus by affecting the usual production, storage and release of ADH. An inherited genetic disease also can cause this condition.

• Nephrogenic diabetes insipidus. Nephrogenic diabetes insipidus occurs when there's a defect in the structures in your kidneys that makes your kidneys unable to properly respond to ADH.

  The defect may be due to an inherited (genetic) disorder or a chronic kidney disorder. Certain drugs, such as lithium or antiviral medications such as foscarnet (Foscavir), also can cause nephrogenic diabetes insipidus.

• Gestational diabetes insipidus. Gestational diabetes insipidus is rare. It occurs only during pregnancy when an enzyme made by the placenta destroys ADH in the mother.

• Primary polydipsia. Also known as dipsogenic diabetes insipidus, this condition can cause production of large amounts of diluted urine from drinking excessive amounts of fluids.

  Primary polydipsia can be caused by damage to the thirst-regulating mechanism in the hypothalamus. The condition has also been linked to mental illness, such as schizophrenia.

Sometimes, there's no obvious cause of diabetes insipidus. However, in some people, the disorder may be the result of an autoimmune reaction that causes the immune system to damage the cells that make vasopressin.