Diabetes insipidus (DI) is a condition in which a person produces inappropriately large amounts of urine, and becomes continually thirsty and drinks high volumes of liquids in order to replace body water. It is an entirely different condition from diabetes mellitus, the disease commonly referred to as "diabetes".
When a person has diabetes insipidus, it is almost as if everything he or she drinks passes right through the kidneys.
The 3 forms of DI are: central or neurogenic, in which a defect in the brain causes a shortage of 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 to vasopressinpregnancy-induced, in which there is a low level of vasopressin during the pregnancy
Symptoms of diabetes insipidus include: excessive urination: anywhere from 4 to 16 liters a day or moreexcess thirstinability to quench thirstdry skin and mucous membranesconstipationmuscle weaknessdehydration, causing dizziness and general weaknessthe need to urinate during the nightfatigue from getting up to urinate during the night
Diabetes insipidus may be caused by: a brain tumor, which keeps the body from producing enough vasopressinskull fracturehead injury causing damage to the pituitary gland, the part of the brain that releases vasopressincraniotomy, or surgery on the headinfections, such as encephalitis or meningitis, that damage the pituitary gland or brainkidney diseasesome medications, such as lithiuminadequate release and response to vasopressin during pregnancy
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.
Diagnosis of diabetes insipidus is usually based on the medical history, physical exam, lab tests, and imaging tests. Urine tests, including a water deprivation test, will often be used when DI is suspected. With this test, water is withheld until the person loses a certain percentage of his or her body weight. Blood and urine tests are checked routinely to evaluate the reaction of the body to the lack of water. Ultrasound,MRI, and CT scan are commonly used imaging tests to check for brain injury, tumors, or kidney problems.
Long-term effects depend on the cause of the diabetes insipidus. For instance, if the cause of the DI is a head injury and a person recovers completely from the injury, there may be no long-term effects.
Diabetes insipidus is not contagious and poses no risk to others. However, those who are affected may sometimes pass the condition on to their children. Genetic counseling may be helpful to couples with a family history of diabetes insipidus.
Treatment of diabetes insipidus will depend on the cause. For instance, a person may need antibiotics for an infection. In other people, control of DI will involve use of different types of vasopressin, given as an injection into the muscle (i.e., Pitressin) or desmopressin (i.e., DDAVP) 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 prescribed to keep the fluids in the body balanced. If other conditions are present, such as head injury, treatment may involve surgery to repair or relieve pressure on the brain. Those with a brain tumor may need surgery, chemotherapy, or radiation therapy.
Antibiotics can cause stomach upset, headache, or allergic reaction. Vasopressin may cause too much fluid to build up in the body, so fluid intake needs to be watched carefully. Surgery can be complicated by bleeding, infection, or an allergic reaction to the anesthetic. Chemotherapy may cause other side effects, including hair loss and an increased susceptibility to infections.
A person with a head injury may require physical therapy and occupational therapy during recovery. Those with kidney problems may need further treatment, continued medication, and monitoring. A pregnant woman may need no further treatment once she delivers the baby. Those with serious diseases, such as end-stage cancer, may die if treatment does not work.
Any new or worsening symptoms should be reported to the healthcare provider. A person may be advised to watch the amount of fluids he or she drinks and to measure the amount of urine that he or she puts out.
Professional Guide to Signs and Symptoms, Springhouse, 1997.
Harrison's Principles of Internal Medicine, 1998, Fauci, et al.
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