Diabetes insipidus is a condition that affects the kidneys. The latter are unable to retain water and drain too much liquid. Diabetes insipidus is caused by a deficiency of a hormone called antidiuretic hormone or HAD that is secreted by a gland in the brain, the hypothalamus, and stored in another part of the brain, the pituitary gland. The cause of diabetes insipidus is either a neurological disorder - trouble with the secretion or release of the hormone-, or a nephrogenic origin - a poor response of the kidney to the hormone. This diabetes has nothing to do with diabetes mellitus.
Diabetes insipidus occurs as follows:
- a great thirst, resulting in an intense need for water;
- an inability to quench one's thirst;
- very low concentration of urine;
- a urine secretion in abundant amount, up to 8 to 10 liters per day.
The doctor will carry out blood and urine tests. As a follow-up, a brain MRI will be performed to look for a tumor or other abnormality of the hypothalamic-pituitary region that would point to a main cause of diabetes insipidus. In the absence of injury, the patient will be subjected to an experiment in which he will be deprived of water. At first, he will be asked to urinate and then be weighed. Weight, pulse and blood will be monitored frequently, and urine will be collected and analyzed. This practice will obviously be done in a hospital, to be able to respond quickly in case of possible dehydration. A test by administering the HAD is also possible to make the diagnosis.
The treatment of diabetes insipidus is hormonal. It comprises giving the patient a synthetic hormone, desmopressin, which replaces the missing hormone. This treatment is in most cases given for life.
There is no way to prevent diabetes insipidus.