Central diabetes insipidus is completely unrelated to diabetes, even though they share the symptoms of peeing more and feeling thirsty. It’s also called “central DI,” “pituitary DI,” “hypothalamic DI,” “neurohypophyseal DI,” or “neurogenic DI.”
Central DI is much less common than diabetes, and treatments for the two diseases are different.
The key sign of central diabetes insipidus is extreme thirst and excessive urination. The disease happens when the body doesn’t make enough of the hormone vasopressin, which controls how much urine the kidneys put out.
Without vasopressin, the kidneys can’t work properly. As a result, the body loses a lot of water, quickly, in diluted urine. This makes people very thirsty, so they drink lots of water.
Anyone can get central DI, but it’s not common. Only about 1 in every 25,000 people gets it.
In about half the cases, doctors don’t know what causes central DI. Other times, it happens because of damage or injury to the hypothalamus or pituitary gland. This damage can be due to surgery, head trauma, tumour, inflammation, or infection. In exceedingly rare cases, genetic defects are the cause.
Prompt treatment of injuries, infections, and tumours can lower the odds of getting the disease.
People with central DI usually have the following symptoms:
In severe cases, or if a person can’t get enough liquid to drink, central diabetes insipidus can cause:
Symptoms of central DI in children may be:
A check-up may not show any signs of central DI, except perhaps for an enlarged bladder or symptoms of dehydration.
If your doctor thinks you have central DI, he will test a sample of your urine. You will also take a water restriction test, which usually involves staying at a hospital to check on how well your kidneys work, how much urine you make, and how much sodium is in your plasma. You may get vasopressin and then take more blood and urine tests. Your doctor may also recommend that you get an MRI of your head, to see if there are any problems in or around your pituitary gland.
If your central DI is mild, the treatment for central DI is simple: Drink more water.
In some cases, your doctor may prescribe desmopressin or DDAVP, which is a type of vasopressin. Desmopressin controls urine output, maintains fluid balance, and prevents dehydration. You take it two to three times a day, usually as a nasal spray, tablets, or injections.
Carry your medication with you and avoid situations where you can’t get water. It’s also a good idea to wear “medic alert” jewellery, or keep a note with you about your condition, so that health care workers know about it.