by Erich Rosenberger M.D.

Created on: December 02, 2008

Most people have heard of diabetes. In addition, most people are aware that there are two common sub-types of diabetes. But did you know that there is another type of diabetes that is completely different than the one most people associate with the word diabetes? The household term "diabetes" actually refers to diabetes mellitus. However, there is also a disorder known as diabetes insipidus. Diabetes insipidus is completely different from diabetes mellitus in cause and treatment.

In diabetes mellitus, a person has either a lack of insulin production, or a resistance to insulin action on the cells of the body. With diabetes insipidus, there is a lack of another hormone - vasopressin.

There are two major types of diabetes inspidus, central and nephrogenic. (Actually there are four, but these two are the most common)

Central diabetes insipidus involves a lack of the hormone vasopressin. This deficience can be caused by a lesion on the pituitary gland or the hypothalamus. It is possible for this to be an inherited (genetic) disorder. Central diabetes insipidus can also be caused by damage to the brain, infections, and tumors.

Nephrogenic diabetes insipidus involves defects in the kidneys. These defects interfere with the ability of the kidney to respond to the hormone vasopressin. Vasopressin controls water reabsorption in the kidneys. People who suffer from nephrogenic diabetes insipidus have to urinate a lot as the kidney is not able to properly retain as much water as it should.

Nephrogenic diabetes insipidus can be caused by a variety of factors. It can be present at birth and inherited genetically. It can also be caused by a wide range of diseases such as kidney infections, some cancers, sickle cell anemia, and a wide range of other problems which damage the kidneys. It can also be caused by certain medications such as corticosteroids, diuretics, and even some antibiotics.

So what does does vasopressin do?

Vasopressin is a hormone which controls the amount of matter that your body retains in the kidneys. The lack of vasopressin, or the kidney's lack of response to vasopressin, will lead to excessive urine output. People with diabetes insipidus will urinate large volumes of very clear urine every day. They will also be chronically thirsty. It is not uncommon for a person with diabetes insipidus to urinate 2 to 20 liters of fluid day. This means they will also need to drink approximately the same amount. It is possible in some cases for a person to become chronically dehydrated and have electrolyte imbalances because of this excessive urination.

Treatment for diabetes insipidus depends on the type and severity. Mild cases can often be treated with adequate water intake. In cases caused by medications or infections, it is important to discontinue those medications and/or treat the infection. Central diabetes insipidus requires the use of a medication known as desmopressin. Desmopressin can be taken either by mouth, or inhaled through the nose. Nephrogenic diabetes insipidus will require different medications as desmopressin will not solve the problem. As with most disorders, it is important to customized treatments to a specific patient.

Your doctor has a wide range of tests available to determine if you are suffering from diabetes insipidus. This article is intended to be a very short introduction to diabetes insipidus. It is not a comprehensive overview of the disease. If you have further questions about diabetes insipidus, how it is diagnosed, or how it is treated, be sure to speak with your physician. It is important to note that diabetes insipidus is in no way related to diabetes mellitus.

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