Diabetes Insipidus

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
    mother.

What are the symptoms of diabetes insipidus?

Common symptoms may include:

  • Being very thirsty
  • Urinating a lot
  • Dehydration

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.