What Is Diabetes Insipidus?

    Diabetes insipidus (DI) is a rare condition that occurs when your kidneys are not able to conserve water. It results in extreme thirst for water and frequent urination. There are several types of DI, and they can often be successfully treated.

    This condition is not related to diabetes mellitus (the disease most often referred simply as “diabetes”).

    What Causes Diabetes Insipidus?

    Diabetes Insipidus is caused by a disruption in the processes that regulates fluid in the body.

    Fluids make up as much as 60 percent of overall body mass. Maintaining the proper amount of fluid in the body is key to overall health. Water is needed to balance and regulate the fluid in your body.

    In addition to your intake of water and fluids, the 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 the bloodstream. The bladder stores this fluid waste until it is removed through urination. The body regulates fluid levels by producing less urine when fluid lost to sweating needs to be replaced, or by producing more urine when there is too much fluid in the body.

    The brain regulates this process in several ways. The hypothalamus, a part of the brain, regulates thirst and the need to drink water. The brain also produces an anti-diuretic hormone (ADH), called vasopressin which is stored in the pituitary gland after production. When the body needs to retain water, the pituitary gland will release the vasopressin into the blood stream. When the body needs to get rid of water, the hormone is not released, and the kidneys will cause frequent urination.

    When any part of this regulation system breaks down, it can lead to diabetes insipidus.

    What Are the Types of 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. This damage means that anti-diuretic hormone (ADH) cannot be stored and released normally.

    According to the National Kidney and Urologic Diseases Information Clearinghouse, this type of DI is often the result of head trauma, diseases that cause brain swelling, surgery, tumor, loss of blood supply to the pituitary gland, or genetic conditions (NKUDIC, 2012).

    Nephrogenic Diabetes Insipidus

    This is caused by damage to the kidneys that makes them unable to respond to the ADH.

    It can also be caused by drugs (lithium or tetracycline), high levels of calcium in the body, or other medical conditions such as sickle cell disease, polycystic kidney disease, or genetic conditions.

    Dipsogenic Diabetes Insipidus

    This form of DI is caused by damage to the thirst mechanism in the brain (hypothalamus). Drinking too much liquid can cause this condition, as can sarcoidosis (an inflammatory disease) and mental illness.

    Gestagenic Diabetes Insipidus

    This type of DI occurs only during pregnancy when an enzyme made by the placenta destroys a mother’s own ADH. The placenta plays an important role in the exchange of nutrients and waste products between the fetus and the mother.

    In some cases the cause of DI may be difficult to determine.

    What Are the Risk Factors for Diabetes Insipidus?

    The condition normally occurs in males only, apart from gestational DI. Current studies suggest there may be a genetic link.

    What Are the Symptoms of Diabetes Insipidus?

    The main symptoms of DI are excessive thirst—an uncontrollable craving for water—and excessive urine volume.

    According to the Mayo Clinic, daily urine output may range from 2.6 quarts to 16 quarts. Normal urine output is 1.6 to 2.4 quarts per day (Mayo Clinic, 2010).

    Frequent urination at night is possible, along with bedwetting.

    Possible symptoms in young children and infants include:

    • fussiness and crying
    • unusually wet diapers or bedwetting
    • fever, vomiting, or diarrhea
    • dry skin
    • delayed growth
    • weight loss

    You should contact your healthcare professional immediately if you or your child are experiencing these symptoms.

    How Is Diabetes Inspidus Diagnosed?

    Your doctor will talk to you about your symptoms and determine which tests are necessary. Your doctor may use several tests for diagnosis.

    Urinalysis

    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 stop drinking water for two to three hours before the test. You will then give a urine sample, and your healthcare professional will measure changes in:

    •  body weighturine outputurine composition

    The test is done under close supervision in pregnant women and young children to ensure they don’t lose more than five percent of their body weight.

    Magnetic Resonance Imaging (MRI)

    This uses a machine that takes image of your brain tissue using magnets and radio waves. It will see if there is any damage to the brain tissue that is causing your symptoms.

    Your healthcare professional will look closely at your pituitary gland for any damage or abnormalities.

    Genetic Screening

    This may be performed to look for an inherited form of DI based on your family history.

    How Is Diabetes Insipidus Treated?

    Treatment will depend on the type and severity of DI. In mild cases of DI, the doctor may recommend a specific daily increase in water intake.

    Hormone Treatment

    The most common form of treatment for all DI types is desmopressin. This is an artificial hormone that can be taken by pill, nasal spray, or injection. It is a synthetic form of the hormone vasopressin. While taking this medication, it is important to regulate water intake and drink only when thirsty.

    Desmopressin is often prescribed for gestational DI.

    Drugs and Medication

    For patients with nephrogenic DI, treatment includes taking drugs like hydrochlorothiazide or indomethacin, or a combination of medications called Moduretic. When taking these medications, it is important to drink water only when thirsty.

    If the condition is caused by medications, you will work with your healthcare professional to replace or stop taking these medications. However, do not stop taking any medication without talking with your healthcare professional first.

    Treating Underlying Conditions

    If DI is caused by another condition, such as a tumor or problem with the pituitary gland, your healthcare professional will treat that condition first and then determine if the DI still needs to be treated.

    There is no specific treatment for dipsogenic DI, but treating symptoms or primary mental illness may relieve the symptoms.

    Dietary Changes

    A low-salt diet can help decrease the amount of urine produced by the kidneys.

    Lifestyle Modifications

    Lifestyle modifications are important in the treatment of DI. The most important of these is preventing dehydration. Patients should always carry water with them; child patients should be given water every few hours. Your doctor will help you determine just how much fluid you should be drinking each day.

    Also, carrying a medical alert card in your wallet or wearing a medical bracelet can ensure that others know about your DI in case of an emergency. Because dehydration can occur quickly, those around you should know of your condition.

    What Is the Outlook for Diabetes Insipidus?

    The prognosis depends on the underlying cause of the disorder. When it is treated properly, DI does not cause any severe or long-term complications.

    What Are Potential Complications of Diabetes Insipidus?

    The most common complication of DI is dehydration. It is important to recognize the symptoms of dehydration:

    • dry mouth and skin
    • muscle weakness
    • low blood pressure
    • fever
    • headache
    • rapid heart rate
    • weight loss
    • sunken appearance in eyes and soft spots of children

    Electrolyte imbalance can also occur. The symptoms of this include:

    • fatigue
    • lethargy
    • headache
    • irritability
    • muscle pains

    Patients with dipsogenic DI may drink too much water, which can lead to water intoxication. In extremely rare cases, this can lead to brain damage because it lowers the sodium concentration in the body.