What is diabetes insipidus?
Diabetes insipidus (DI) is a rare condition that occurs when your kidneys are not able to conserve water. DI is not related to diabetes mellitus, which is often referred to simply as diabetes. That means you can have DI without having diabetes. In fact, the condition can occur in anyone.
DI results in extreme thirst and frequent urination of dilute and odorless urine. There are several types of DI, and they can often be successfully treated. Keep reading to learn more about this condition.
The main symptoms of DI are excessive thirst, which can cause an uncontrollable craving for water, and excessive urine volume. A healthy adult will typically urinate less than 3 quarts of urine a day. People with DI may eliminate up to 16 quarts of urine a day.
You may need to get up during the night to urinate frequently, or you may experience bed-wetting.
Possible symptoms in young children and infants include:
- fussiness and irritability
- unusually wet diapers or bed-wetting, or excessive urine output
- excessive thirst
- high fever
- dry skin
- delayed growth
Adults can experience some of the above symptoms, plus confusion, dizziness, or sluggishness. DI can also lead to severe dehydration, which can lead to seizures, brain damage, and even death if not treated.
You should contact your doctor immediately if you or your child is experiencing these symptoms.
To understand diabetes insipidus, it helps to understand how your body normally uses and regulates fluids.
Fluids make up as much as 60 percent of your overall body mass. Maintaining the proper amount of fluid in your body is key to your overall health. Consuming water and food throughout the day helps provide fluid to your body. Urinating, breathing, and sweating help to eliminate fluid from your body.
Your body uses a system of organs and hormone signals to regulate body fluids. The kidneys play an important role in this fluid regulation by removing extra fluid from your bloodstream. The bladder stores this fluid waste until you urinate it out. Your body regulates fluid levels by making less urine when you need to replace fluid lost to sweating, or by making more urine when there is too much fluid in your body.
Your brain regulates this process in a few ways. The hypothalamus, a part of the brain, regulates your feeling of thirst and the need to drink water. The brain also produces an antidiuretic hormone (ADH), also called vasopressin, which is stored in the pituitary gland after production.
When your body needs to retain water, the pituitary gland will release the vasopressin into the blood stream. When you need to get rid of water, the hormone is either released in smaller amounts or not released at all, and you will urinate more often.
When any part of this regulation system breaks down, it can lead to diabetes insipidus.
There are four types of DI:
Central diabetes insipidus
This is the most common form of DI and is caused by damage to the pituitary gland or hypothalamus. This damage means ADH cannot be produced, stored, or released normally. Without ADH, large amounts of fluid are released into the urine.
This type of DI is often the result of:
- head trauma
- diseases that cause brain swelling
- loss of blood supply to the pituitary gland
- rare genetic conditions
Nephrogenic diabetes insipidus
Certain genetic defects can damage the kidneys, making them unable to respond to the ADH.
Nephrogenic diabetes insipidus can also be caused by:
- medications, such as lithium or tetracycline
- high levels of calcium in the body
- low potassium levels in the body
- chronic kidney disease
- urinary tract blockage
Dipsogenic diabetes insipidus
This form of the disease is caused by dysfunction of the thirst mechanism in the hypothalamus. That can cause you to feel excessively thirsty and drink too much liquid. The same things that lead to central DI can lead to dipsogenic diabetes insipidus, and it has also been associated with certain mental illness and other medications.
Gestational diabetes insipidus
This type of DI occurs only during pregnancy when an enzyme made by the placenta destroys a mother’s ADH. It may also be caused by an increased level of a hormone-like chemical that makes the kidneys less sensitive to ADH. The placenta plays an important role in the exchange of nutrients and waste products between the fetus and the mother. The condition should resolve after pregnancy.
Your doctor will talk to you about your symptoms and determine which tests are necessary. Your doctor may use several tests for diagnosis, which include:
Your doctor will take a sample of your urine to test for salt and other waste concentrations. If you have DI, your urinalysis will have a high concentration of water and a low concentration of other waste.
Water deprivation test
You will be asked to stop drinking water for a specified period of time before the test. You will then give blood and urine samples and your doctor will measure changes in:
- blood sodium and osmolality levels
- body weight
- urine output
- urine composition
- ADH blood levels
The test is done under close supervision, and may require hospitalization in certain people to ensure it’s done safely.
Magnetic resonance imaging (MRI)
This test uses a machine that will take an image of your brain tissue using magnets and radio waves. Your doctor will then look at these images to see if there’s any damage to the brain tissue that is causing your symptoms.
Your doctor will also look closely at images of your hypothalamus or pituitary gland for any damage or abnormalities.
This screening may be performed to look for an inherited form of DI based on your family history.
Treatment will depend on which type of DI you are diagnosed with and the severity of your condition. In mild cases of DI your doctor may recommend that you manage your water intake to a specific amount per day.
The most common form of treatment for all DI types is desmopressin (DDAVP). This is an artificial hormone that can be taken by pill, nasal spray, or injection. It’s a synthetic form of the hormone vasopressin. While taking this medication, it’s important to regulate your water intake and drink only when you are thirsty.
Desmopressin is used to treat central DI and may be prescribed for severe gestational DI.
Drugs and medication
In nephrogenic DI, treating the cause may cure the problem. Other treatments include taking high doses of desmopressin, along with other drugs like diuretics, either alone or with aspirin or ibuprofen, or other types of this medication class such as indomethacin (TIVORBEX). When taking these medications, it’s important to drink water only when you’re thirsty.
If the condition is due to medications you’re taking, your doctor will work with you to replace or stop taking these medications. But don’t stop taking any medication without talking with your doctor first.
Treating underlying conditions
If your DI is caused by another condition such as a tumor or problem with the pituitary gland, your doctor will treat that condition first and then determine if the DI still needs to be treated.
There isn’t a specific treatment for dipsogenic DI, but treating symptoms or primary mental illness may relieve the symptoms.
Lifestyle modifications and dietary changes
Lifestyle modifications are important in the treatment of DI. The most important is preventing dehydration. You can do this by bringing water with you wherever you go or offering water every few hours to your child if they have DI. Your doctor will help you determine how much fluid you should be drinking each day.
Carry a medical alert card in your wallet or wear a medical bracelet so that others know about your DI in case of an emergency. Dehydration can happen quickly, so those around you should know of your condition.
The outlook depends on the underlying cause of the DI. When it is treated properly, this condition does not typically cause any severe or long-term complications.