Diabetes insipidus (DI) is a rare disease where the body cannot regulate its fluids properly. While DI shares its name (and some symptoms) partially with diabetes mellitus, the underlying conditions have nothing to do with one another. The overriding characteristic or symptom of DI is that the person experiences a tremendous increase in urine production. A common misspelling of the condition is diabetes insipidis.
So, what exactly is DI? First, let’s take a look at how your body deals with fluids. The body has a complex method of regulating its fluid levels. If fluid levels drop, the body signals you to become thirsty, so you drink more.
If fluid levels are too high, then the kidneys produce urine, which is then passed as waste. Additionally, if fluid levels drop or are needed elsewhere (for example, if you are sweating), then less urine is produced.
This last process is regulated by a hormone called vassopresin or antidiuretic hormone (ADH) made in the hypothalamus gland located in the brain. ADH is stored in the pituitary gland and released when needed.
4 Different Types
DI occurs when either the thirst or ADH regulatory process breaks down. There are four different types of DI.
Central Diabetes Insipidus. This is the most common and most dangerous form of DI. The pituitary gland is damaged and cannot properly store or release ADH. Generally, this damage occurs from a number of diseases or genetic disorders or from injury to the head or during surgery. The synthetic hormone desmopressin is usually prescribed. Desmopressin limits water excretion. The danger with the drug is that you should only drink when thirsty, otherwise excess fluid can build up.
Gestational DI. As the name suggests, gestational diabetes insipidus occurs during pregnancy. The placenta can release an enzyme that eliminates ADH in the mother. This is the normal way Gestational DI develops and is usually treated with desmopressin.
Occasionally, the thirst mechanism, not ADH, is affected, in which case desmopressin is inappropriate. Obviously, this is not a self treatment condition, so check with your doctor for proper diagnosis and treatment.
Dipsogenic DI. Dipsogenic is caused by a damage or defect in the thirst process. Thirst is dramatically increased causing fluid intake to rise dramatically. Correspondingly, these increases serve to suppress ADH production. The result is a huge increase in urine production.
Desmopressin should not be given, as this can cause a decrease in urine production, but no decrease in thirst or fluid intake. The result would be a lot of excess fluid in the body with nowhere to go, possibly causing water intoxication. Water intoxication can lower sodium levels, potentially causing brain damage. There is no definitive or effective treatment for dispogenic DI.
Nephrogenic Diabetes Insipidus. This condition results when the kidneys are resistant to ADH. Causes can include certain drug intake (for example, lithium) and chronic or genetic disorders. Desmopressin is not an effective treatment, but other drugs (or combination thereof) such as hydrochlorothiazide (HCTZ), indomethacin and amiloride may be appropriate. Fluid intake should only coincide with thirst.
The treatment for diabetes insipidus is usually fairly straight forward. For fluid loss, in many instances, drinking more water is the necessary treatment to counteract the loss of fluid due to excessive urination. It is imperative, however, that fluid replenishment is done appropriately.
Too much fluid, too fast can cause problems, as can not receiving enough fluids in a timely manner. For emergency cases, it is best to consult with your physician. Additionally, certain fluid additives, such as sodium and dextrose may be necessary.
If inadequate thirst is the issue, then treatment with desmopressin is typically given to reduce urination. Fluid intake is also required to ensure that fluid levels are at an appropriate level. Occasionally, hospitalization is required to determine an appropriate balance.
Some people ask about dietary requirements. Generally, no particular diet is needed or recommended. However, depending upon the circumstances, DI patients should be aware of electrolyte and sodium balances in the body. Maintaining sodium and electrolytes at appropriate levels is important.
Another issue is extreme exertion. Extreme exertion can cause you to sweat excessively. Again, replacing your fluid levels requires special monitoring to ensure you do not replace them too quickly.
Lastly, being aware of problems that can occur if sick is also important. Vomiting and diarrhea can lead to dehydration, so you need to be particularly vigilant under these circumstances, especially if traveling abroad.
National Institute of Health, Diabetes Insipidus, NIH.gov (accessed February 2013).
Diabetes Insipidus: Treatment and Medication, Michael Cooperman, M.D., emedicine.medscape.com (February 2008).
By Erich Schultz – Last Reviewed February 2013.