What is diabetes insipidus?
Diabetes insipidus occurs when your
body doesn’t make enough antidiuretic hormone (ADH). Or your kidneys don’t respond to
it. ADH is a hormone that helps keep the right amount of water in your body. It does
this by controlling how much urine your kidneys put out. ADH is made by a small gland
at the base of the brain (hypothalamus). It is stored in the pituitary gland. It’s sent
into the bloodstream when your body’s fluid level is low. This keeps you from losing too
much water (dehydrated). If you are a bit dehydrated, ADH should increase.
Diabetes insipidus is not related
to the more common type of diabetes (diabetes mellitus).
What causes diabetes insipidus?
There are several types of diabetes insipidus:
Central. This is when the pituitary
doesn’t make or send out enough ADH. It can happen if the hypothalamus or pituitary
gland are damaged. That can be caused by a head wound, including surgery on the
pituitary gland. It can also be cause by a genetic problem or other diseases.
Nephrogenic. This is when the kidneys
don’t respond to normal levels of ADH. It can be caused by medicines, or lifelong
(chronic) disorders such as kidney disease or sickle cell disease. It can also be
caused by low potassium or high calcium levels in the blood.
Dipsogenic. This is when there is
damage to the mechanism that controls thirst, found in the hypothalamus. You are then
too thirsty and drink too many fluids. This slows down ADH production.
Gestational. This occurs only in
pregnant women. In this type, an enzyme made by the placenta destroys ADH in the
What are the symptoms of diabetes insipidus?
Common symptoms may include:
- Being very thirsty
- Urinating a lot
These symptoms may look like other health problems. Always see your healthcare provider for a diagnosis.
How is diabetes insipidus diagnosed?
Your provider will take your health history and give you a physical exam. You may also need the following tests:
- Urine tests
- Blood tests to see how your pituitary
and kidneys react to dehydration. This is called a formal water deprivation test. Or
you may have an IV infusion of a concentrated salt solution.
- CT scan or MRI. You may need this to see if you have a
structural problem in the hypothalamus or pituitary gland.