Diabetes Insipidus - Diagnosis

Diabetes Insipidus is not the same as the Diabetes Mellitus that we hear of so regularly. However, given the impact it has on affected people (the kidneys are unable to concentrate urine, causing excessive urination and extreme thirst), it is important that the disease is diagnosed early and accurately.
In order to distinguish DI from other causes of excess urination, blood glucose levels, bicarbonate levels, and calcium levels need to be tested. Measurement of blood electrolytes can reveal a high sodium level (hypernatremia as dehydration develops). Urinalysis demonstrates a dilute urine with a low specific gravity. Urine osmolarity and electrolyte levels are typically low. Urinalysis is the physical and chemical examination of urine. The urine of a person with DI will be less concentrated. Therefore, the salt and waste concentrations are low and the amount of water excreted is high. A physician evaluates the concentration of urine by measuring how many particles are in a kilogram of water or by comparing the weight of the urine with an equal volume of distilled water. To put this in detailed form; Some of the tests that doctors commonly use to determine the type of diabetes insipidus and in some cases, its cause, include:
1. Water deprivation test. This test helps determine the cause of diabetes insipidus. You'll be asked to stop drinking fluids two to three hours before the test so that your doctor can measure changes in your body weight, urine output and urine composition when fluids are withheld. In some cases your doctor may also measure blood levels of ADH during this test.
2. The water deprivation test is performed under close supervision in children and in pregnant women to make sure no more than 5 percent of body weight is lost during the test.
3. Urinalysis. Urinalysis is the physical and chemical examination of urine. If your urine is less concentrated (meaning the amount of water excreted is high and the salt and waste concentrations are low), it could be due to diabetes insipidus.
Magnetic resonance imaging (MRI) scan. An MRI of the head is a noninvasive procedure that uses powerful magnets and radio waves to construct detailed pictures of brain tissues. Your doctor may want to perform an MRI to look for abnormalities in or near the pituitary gland.

Just to keep in mind, the following is the profile of people likely to have a greater chance of contracting this problem.
- Diabetes insipidus most frequently occurs in persons in their 20s, more often in males than females.
- The disorder may run in families, though the cause is unknown.
- Diabetes insipidus can occur after an injury to the head; brain surgery; cancer; sarcoidosis, causing destruction of the pituitary gland; the use of certain medications that decrease ADH production; excessive use of alcohol; and any condition or illness that causes decreased oxygen delivery to the brain.
- Diabetes insipidus may also occur in women who are pregnant or have just given birth, and in patients with AIDS who have suffered certain types of brain infections.