Cortisol is a hormone produced by the supra renal glands, whose secretion is stimulated by ACTH (adrenocorticotropic hormone) – hormone produced by a small organ located below the cerebral mass. Cortisol has many different roles in the body: helps protein burn, glucose and lipids; helps regulates blood pressure and maintain immune system activity.

The amount of cortisol is secreted by a daily pattern in the first hours of the morning when its maximum value is reached and at around 8 in the afternoon declines. This pattern bears the name change or subsistence and circadian rhythm changes periodicity in the daily activities of disorder (lack of sleep during the night and sleep the afternoon).

Disturbed quantities of cortisol can cause symptoms without a specific way, such as weight loss, muscle weakness, fatigue, decreased arterial pressure and abdominal pain. Sometimes, a low hormone production combined with the stress factor causes a supra renal crisis that requires immediate medical attention.

A high level of cortisol causes increased blood pressure, blood glucose of appearance obesity, skin sensitivity, muscle weakness and osteoporosis.

Indications:

Cortisol test, made of blood and urine is performed for diagnosis of Cushing syndrome and Addison disease, which are serious malfunction of the endocrine glands. Some doctors are using saliva as a sample way for making the test, for Cushing syndrome and to detect disturbances that may be caused by stress. But the most common tests for cortisol are made from urine and saliva, especially for cases of excess hormone.

With the detection of abnormal levels of cortisol, the doctor recommends carrying out additional tests to confirm the excess or deficiency and to determine the cause.

Dexamethasone Suppression

In case of cortisol excess the doctor may recommend a dexamethasone suppression test to determine whether it is related to the increased levels of ACTH. Oaral tests involves the administration of dexamethasone (a synthetic glucocorticoid), followed by measuring levels of cortisol in blood and urine. Dexamethasone suppress production of ACTH and a decrease in the cortisol where this factor is related to excess pituitas gland.

Regarding drug dosage, there are many variations but it is usually given once every 6 hours with 2 or 4 days before collecting the blood or urine. Separately collected urine for 24 hours before and during testing, and samples of blood and urine for cortisol are measured and analyzed.