Diabetes insipidus is entirely different from diabetes mellitus, or what most people refer to simply as "diabetes." Diabetes insipidus is marked by the frequent production of large amounts of urine, which is typically clear and very dilute. Diabetes inspidus can result from problems with the brain or the kidneys, or from other endocrine abnormalities.
Central
Central diabetes insipidus, according to the Mayo Clinic, is due to inadequate production of the hormone ADH, which is also known as antidiuretic hormone or vasopressin. This can occur when the pituitary or the hypothalamus is damaged, which can happen as the result of a head injury, surgery, certain kinds of infections--such as meningitis--or a tumor. When this happens, the kidneys do not get adequately stimulated to reabsorb water, which leads to increased urine, dehydration and constant thirst.
Nephrogenic
Nephrogenic diabetes insipidus, according to the Children's Hospital of Philadelphia, is caused by a problem with the kidneys themselves. Patients with nephrogenic diabetes inspidus are able to produce ADH, but the kidneys do not respond to it. This can be a result of drugs, such as lithium or tetracycline, which cause the kidneys to ignore ADH signaling. It can also be caused by certain chronic conditions, such as sickle cell disease, polycystic kidney disease and kidney failure.
Gestational
Gestational diabetes insipidus occurs only in pregnant women. During pregnancy, the placenta, which is a cluster of blood vessels and supportive tissue in the uterus, can make an enzyme that circulates through the mother's body and breaks down ADH. This variety of diabetes inspidus can be treated with the administration of synthetic ADH.
Dipsogenic
Dipsogenic diabetes insipidus, according to the National Institute of Diabetes and Digestive and Kidney Disorders, results when the hypothalamus is damaged, causing dysfunction of the thirst response. Patients become very thirsty and consume lots of fluids, which in turn blocks ADH production. Patients with this form of diabetes inspidus should not be treated using synthetic ADH, because it will not lower the patient's fluid intake.
