Symptoms & Causes
Diabetes insipidus is a rare condition which causes the kidneys to produce large quantities of very dilute urine. This excessive urination is the principal symptom of the condition, and gives rise to its informal name of water diabetes.
In addition to excessive urination, common symptoms include intense thirst, dehydration, and a frequent need to urinate that can disrupt sleep and even cause bedwetting. Children with water diabetes are often listless and irritable, and may have diarrhea, vomiting, or fever.
Diabetes insipidus can have one of four causes:
Dipsogenic diabetes insipidus is caused by excessive thirst, which causes the individual to drink large amounts of water.
Neurogenic forms of the condition are caused by a deficiency in a hormone called vasopressin, which controls urine output. Vasopressin is an anti-diuretic hormone which helps control the urine output of the kidneys by providing a chemical signal that tells the kidneys to excrete less water when it is needed by the body. When vasopressin is absent the kidneys consistently produce large amounts of urine, even at night when the body would normally produce less urine.
Nephrogenic diabetes insipidus occurs when the kidneys become resistant to vasopressin.
Gestagenic diabetes insipidus occurs only during pregnancy, as a result of a temporary vasopressin deficiency.
Note that all of these differ markedly from the cause of the much more well-known diabetes mellitus, which occurs as a result of insulin resistance or deficiency and leads to high blood sugar.
It is rare for water diabetes to be so severe that health is impaired. For most people with the condition, the only treatment that is needed is to drink much larger than normal amounts of water – two or more liters a day – to replace the excessive amount of water that is excreted.
Treatment may also depend on the type of diabetes insipidus that is causing the symptoms. Treatment with vasopressin may be appropriate for neurogenic or gestagenic forms of the disease, for example, but won’t be effective for the nephrogenic or dipsogenic forms of the disease.
National Institute of Health Kidney and Urologic Diseases Information: Diabetes Insipidus
National Institute of Health MedlinePlus: Diabetes Insipidus