Reasons & Procedure For Conducting a Urine Cortisol Test
Submitted on March 27, 2012
Cortisol in urine or in blood is checked to diagnose Addison’s diseases or the cushing’s syndrome. The test is usually performed in order to check for excessive production of cortisol. If the concentration of cortisol is detected to be abnormal, some additional testing may be required to confirm whether the abnormality is caused due to an excess or a deficiency. The cause of this abnormality is also determined by separate tests.
Reason Why It is Performed
An excess of cortisol is detected by a dexamethasone suppression test. This test can also help determine the cause of this excess. Usually, the excess is caused due to increased ACTH production by the pituitary glands. In this test, oral dexamethasone is given to a patient and then the cortisol levels in the blood and the urine are tested.
For a test which indicates insufficient cortisol in blood or urine, an ACTH stimulation test may be used as a follow up to determine the cause of this deficiency. In this test, the patient is injected with synthetic ACTH and the blood cortisol levels are checked both before and after injecting the chemical.
The urine free cortisol test is usually ordered when there are symptoms that are suggestive of either Addison’s disease or Cushing’s syndrome. When the doctor observes symptoms like obesity, wasting of muscles, weakness, fatigue, or increase in pigmentation, a 24 hour urine cortisol test is usually conducted. If the test results of this test are abnormal, a suppression or stimulation test is ordered next.
Later, once the disorder is diagnosed, further tests are conducted to monitor the course of the disease and the efficiency of the treatment. Cortisol levels are rather low in normal people. However, at bed time, the levels increase. It is because of this that a 24 hour urine sample is required for the test.
In Cushing’s syndrome, there is no set patter of cortisol production. There may be increased production in the morning without the levels dropping around the afternoon. Certain conditions like pregnancy, infections, long term illnesses or emotional stress may increase the production of cortisol in the body. Persons suffering from hyperthyroidism and those who are obese may also have higher levels of cortisol.
Medications that include hydrocortisone, oral contraceptives etc may also increase cortisol levels. Normally adults have higher levels of cortisol than children therefore the reference range is different for both. Conditions like hypothyroidism and medications which are steroid based may decrease urine cortisol levels and affect the results.