Diabetes Insipidus

Overview, Causes, & Risk Factors

Diabetes insipidus (DI) is a condition in which a person is thirstyall the time, drinks large amounts of fluids, and produces large amounts of urine. It is not the same condition as the more commonly known diabetes mellitus.

What is going on in the body?

When a person has diabetes insipidus, it is almost as if everything he or she drinks passes right through the kidneys. The 4 forms of DI are:

  • central or neurogenic, in which a defect in the brain causes a shortageof vasopressin, or antidiuretic hormone (ADH). This hormone normally tells the kidneys how much urine to release.
  • nephrogenic, in which a kidney defect causes an abnormal response tovasopressin
  • pregnancy-induced, in which there is a low level of vasopressin duringthe pregnancy
  • primary polydipsia, which is an abnormally high level of thirst and fluidintake
  • What are the causes and risks of the disease?

    Diabetes insipidus may be caused by:

  • brain tumor, which causes the body to produce less-than-enough vasopressin
  • skull fracture
  • head injury causing damage tothe pituitary gland, the part of the brain that releases vasopressin
  • craniotomy, or surgery on the head
  • infections, such as encephalitisor meningitis, that damage thepituitary gland or brain
  • kidney disease
  • some medications, such as lithium
  • inadequate release and response to vasopressin during pregnancy
  • Symptoms & Signs

    What are the signs and symptoms of the disease?

    Symptoms of diabetes insipidus include:

  • excessive urination: anywhere from 4 to 16 liters a day or more
  • excess thirst
  • inability to quench thirst
  • dry skin and mucous membranes
  • constipation
  • muscle weakness
  • dehydration, causing dizziness and general weakness
  • the need to urinate during the night
  • fatigue from getting up tourinate during the night
  • Diagnosis & Tests

    How is the disease diagnosed?

    Diagnosis of diabetesinsipidus is usually based on the medical history, physical exam, lab tests,and imaging tests. Urine tests, including a water deprivation test, will oftenbe used when DI is suspected. With this test, water is withheld until theperson loses a certain percentage of his or her body weight. Blood and urinetests are checked routinely to evaluate the reaction of the body to the lack ofwater. Ultrasound,MRI, and CT scan are commonly used imaging tests to check for brain injury, tumors, or kidney problems.

    Prevention & Expectations

    What can be done to prevent the disease?

    It is hard to prevent diabetes insipidus. A person can reduce his or her risk of head injury by following sports safety guidelines for children, adolescents, and adults. Early treatment of infections may also reduce the risk of DI.

    What are the long-term effects of the disease?

    Long-term effectsdepend on the cause of the diabetes insipidus. For instance, if the cause ofthe DI is a head injury and a person recovers completely from the injury, there may be no long-term effects.

    What are the risks to others?

    Diabetes insipidus is notcontagious and poses no risk to others. However, those who are affected may sometimespass the condition on to their children. Genetic counseling may be helpful to couples with a family history of diabetes insipidus.

    Treatment & Monitoring

    What are the treatments for the disease?

    Treatment of diabetes insipiduswill depend on the cause. For instance, a person may need antibiotics for aninfection. In other people, control of DI will involve use of different typesof vasopressin, given as an injection into the muscle or through a nasal spray. Drinking enough fluids will also be essential to prevent dehydration.

    If the DI is caused by problems in the kidneys, a water pill may be prescribedto keep the fluids in the body balanced. If other conditions are present, suchas head injury, treatment may involvesurgery to repair or relieve pressure on the brain. Those with a brain tumor may need surgery, chemotherapy, or radiation therapy.

    What are the side effects of the treatments?

    Antibioticscan cause stomach upset, headache, orallergic reaction. Vasopressin maycause too much fluid to build up in the body, so fluid intake needs to bewatched carefully. Treatments that require surgery pose a risk of bleeding,infection, and allergic reaction toanesthesia. Chemotherapy may causemore side effects, including hair lossand increased risk of infections.

    What happens after treatment for the disease?

    A person with a head injury may require physical therapy and occupational therapy during recovery. Those with kidney problems mayneed further treatment, continued medication, and monitoring. A pregnant woman may need no further treatmentonce she delivers the baby. Those with serious diseases, such as end-stagecancer, may die if treatment does not work.

    How is the disease monitored?

    Any new or worseningsymptoms should be reported to the healthcare provider. A person may be advisedto watch the amount of fluids he or she drinks and the amount of urine that heor she makes.

    Article type: xmedgeneral