- Central diabetes insipidus. The cause of central diabetes insipidus in adults is usually damage to the pituitary gland or hypothalamus, most commonly due to surgery, a tumor, an illness (such as meningitis), inflammation or a head injury. For children, the cause is often an inherited genetic disorder. In some cases the cause is unknown. This damage disrupts the normal production, storage and release of ADH.
- Nephrogenic diabetes insipidus. Nephrogenic diabetes insipidus occurs when there’s a defect in the kidney tubules — the structures in your kidneys that cause water to be excreted or reabsorbed. This defect makes your kidneys unable to properly respond to ADH. The defect may be due to an inherited (genetic) disorder or a chronic kidney disorder. Certain drugs, such as lithium and demeclocycline (a tetracycline antibiotic), also can cause nephrogenic diabetes insipidus.
- Gestational diabetes insipidus. Gestational diabetes insipidus occurs only during pregnancy and when an enzyme made by the placenta — the system of blood vessels and other tissue that allows the exchange of nutrients and waste products between a mother and her baby — destroys ADH in the mother.
- Primary polydipsia. This condition — also known as dipsogenic diabetes insipidus or psychogenic polydipsia — can cause excretion of large volumes of dilute urine. Rather than a problem with ADH production or damage, the underlying cause is intake of excessive fluids. Prolonged excessive water intake by itself can damage the kidneys and suppress ADH, making your body unable to concentrate urine. Primary polydipsia can be the result of abnormal thirst caused by damage to the thirst-regulating mechanism, situated in the hypothalamus. Primary polydipsia can also be caused by mental illness.
In some cases of diabetes insipidus, doctors never determine a cause.
- Extreme thirst
- Excretion of an excessive amount of diluted urine
- Depending on the severity of the condition, urine output can range from 2 quarts (about 2 liters) a day if you have mild diabetes insipidus to 21 quarts (about 20 liters) a day if the condition is severe and if you’re drinking a lot of fluids. In comparison, the average urine output for a healthy adult varies, but is in the range of 1.6 to 2.6 quarts (about 1.5 to 2.5 liters) a day.
- Other signs may include needing to get up at night to urinate (nocturia) and bed-wetting.
- Unexplained fussiness or inconsolable crying
- Unusually wet diapers
- Fever, vomiting or diarrhea
- Dry skin with cool extremities
- Delayed growth
- Weight loss