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Diabetes insipidus Causes and Risks:
Diabetes insipidus is a rare condition that can be caused by a lack of antidiuretic hormone ( vasopressin ), in which case it is classified as central diabetes insipidus . It can also be caused by a defect in the kidney tubule ( nephrogenic diabetes insipidus ). Major symptoms are extreme thirst and excessive urine output .
Antidiuretic hormone
(vasopressin) is a hormone that is normally produced in the hypothalamus of the brain. It controls the way the kidneys remove, filter, and reabsorb fluids into the blood stream. When there is a lack of this hormone (or when the kidneys cannot respond to the hormone), fluids pass through the kidneys and are lost through urination. Therefore, a person with diabetes insipidus must drink large quantities of water in response to extreme thirst, to compensate for the water loss.
Central diabetes insipidus is caused by damage to the hypothalamus as a result of surgery, infection, tumor , or head injury . Although rare, this is the most common form of DI.
Nephrogenic diabetes insipidus involves a defect in the part of the kidneys (the tubules) that reabsorbs water back into the blood stream. It is much more rare than central DI, and occurs primarily as an inherited disorder that usually affects men, although women can pass the gene on to their children. It can also develop as a complication of other disorders that affect the kidney structures.
If thirst mechanisms are normal and adequate fluids are consumed, there are no significant effects on the fluid and/or electrolyte balance of the body. If inadequate fluids are consumed, the high urine output may cause dehydration and high blood sodium.
Symptoms:
Signs and Tests:
Treatment:
The cause of the underlying condition should be treated.
All cases should be treated with consistently high fluid intake. The volume of fluids consumed should approximately equal the volume of urine produced.
Vasopressin therapy (desmopressin), administered as a nasal spray, can control the urine output and fluid balance, thereby preventing dehydration for people with central DI. It is ineffective for nephrogenic DI; other medications (including hydrochlorothiazide) may be effective in controlling this form of the disorder.
Prognosis:
The outcome is dictated by the underlying disorder. If treated, diabetes insipidus does not cause severe problems or reduce life expectancy.
Complications:
Inadequate fluid consumption can result in:
Call Your Healthcare Provider:
Call your health care provider if symptoms indicate diabetes insipidus may be present.
If you have diabetes insipidus, call if complications develop.
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