Diabetes insipidus (DI) occurs when there is a deficiency of the antidiuretic hormone (vasopressin) due to a disorder of the hypothalamus and the pituitary gland. The result is polyuria and polydipsia.

In half of the cases of DI, labeled primary or central vasopressin sensitive, the cause is unknown. The remainder of cases is secondary, or acquired DI, and is caused by injury or tumor in the pituitary gland.

A 5 to 10 liter urine output in 24 hours and excessive thirst are the only symptoms in primary DI. In secondary or acquired DI, signs and symptoms reflect the areas that are involved. Urinary losses of fluid must be replaced in order to avoid dehydration and hypovolemia.

The most reliable test is the water deprivation test. A normal response to water deprivation is one in which urine concentration would exceed plasma concentration. This does not occur in DI.

Causative factors need to be investigated and treated, if possible, to prevent renal damage. If there is not a specific cause, then vasopressin replacement therapy is started. Vasopressin is given parenterally, or by nasal spray because it is ineffective as an oral medication.

This is a chronic disease but, if treated, is not life-threatening.

• Consider service connection on a presumptive basis as a chronic condition (38 CFR §3.307; §3.309 (a)). 

• Note: After three months after initial diagnosis, if diabetes insipidus has subsided, rate residuals under the appropriate diagnostic code(s) within the appropriate body system