Diabetes insipidus is rare disease in which the primary symptom is excessive urine production. When the body is running low on fluids, the pituitary gland signals to the hypothalamus to produce vasopressin, a protein that signals the kidneys to reabsorb fluid as opposed to excreting it in urine. For people with diabetes insipidus, at least one part of this process is disrupted. The symptoms of all types of diabetes insipidus include excreting a large volume of urine; excessive thirst; fever, vomiting, and diarrhea; and irritability and lethargy.
Central Diabetes Insipidus
Central diabetes insipidus is the most common form of diabetes insipidus, according to the National Kidney and Urologic Diseases Information Clearinghous, which is a service of the National Institutes of Health. This disorder results from a damaged pituitary gland. Thus, the hypothalamus does not receive the proper signals to release vasopressin, and the kidneys are not directed to reabsorb fluids, resulting in excessive urine production and the resulting excessive thirst and dehydration.
Nephrogenic Diabetes Insipidus
The Penn State Milton S. Hershey Medical Center describes this form of diabetes insipidus as either a genetic disorder that is inherited from parent to child, or as a result of ingesting substances that are toxic to the kidneys. The kidneys of people with nephrogenic diabetes insipidus do not respond normally to the vasopressin. Normally, the hypothalamus-secreted vasopressin signals the kidneys to reabsorb fluids, but the kidneys of nephrogenic diabetes insipidus do not heed this signal. Thus, the result is a frequent need to urinate, and the production of a large volume of urine excretion.
Gestagenic Diabetes Insipidus
Gestagenic diabetes insipidus occurs while a woman is pregnant, according to the Diabetes Insipidus Foundation, a non-profit group that supports the prevention and cure of diabetes insipidus. Women with this type of diabetes insipidus have too little circulating vasopressin to signal the kidneys to reabsorb fluid. The placenta, the organ full of blood vessels that helps exchange nutrients and waste between the mother and fetus, causes this form of diabetes insipidus. The placenta produces an enzyme that destroys the vasopressin produced by the hypothalamus, ultimately resulting in excess urine production and the lack of fluid reabsorption.
Dipsogenic Diabetes Insipidus
The NKUDIC describes dipsogeneic diabetes insipidus as being caused by damage to the hypothalamus, which regulates feelings of thirst. When the body is in need of fluids, in addition to signaling the kidneys to reabsorb fluid, the hypothalamus induces a feeling of thirst so that he or she will drink more fluids. However, people with dipsogenic diabetes insipidus have a disrupted thirst mechanism that makes them feel excessively thirsty all the time. The person thus drinks an excessive amount of fluids, which may dilute the body's fluids too much. The person may experience water intoxication, which occurs when the levels of electrolytes needed for normal bodily processes are too diluted.
