Ways to Test Cortisol Levels

Cortisol is a hormone that is naturally produced in the human body by the adrenal gland. Cortisol production increases in response to stress and is the cause of elevated blood pressure and increased blood sugar levels during stressful times (The Endocrine Society, 2009). There are three distinct methods used to test the levels of cortisol in the human body: a blood test, a urine test and a saliva test.

Cortisol Blood Test

• Commonly given to adults, this is similar to any other type of blood test. A vein is located and punctured with a needle to begin the flow of blood. The blood is collected in a vial that is sterile and airtight. The needle is removed from your arm, the vial is labeled and sent out for testing, and the puncture mark is covered with a bandage, if necessary (University of California, San Francisco, 2009).

  The blood test to check the cortisol level in infants is different. Rather than using a needle and vial to collect blood, a small, sharp object called a lancet is used. The skin is punctured, and the blood is collected into a small tube made of glass called a pipette or onto a slide. Like the vial, the tube or slide is sent off for testing (University of California, San Francisco, 2009).

Cortisol Saliva Test

• This method is normally reserved for use on patients who are suspected to have Cushing's syndrome. Your doctor might suspect Cushing's syndrome and administer the proper cortisol saliva test if there is evidence of any of the following symptoms: excessive cortisol secretions, unexplained rapid weight gain, high blood pressure, diabetes or hyperlipidemia. Cortisol saliva testing for Cushing's syndrome should be performed late in the evening, between 11 and midnight. Patients with normal cortisol production will have very low levels during this time. If a patient is suspected to have Cushing's syndrome, a high reading late at night will prove the presence of the syndrome.

  This test is performed by collecting your saliva into a tube. The tube is then sent out for testing. While high levels of cortisol at this time of night indicate the definitive presence of Cushing syndrome, the reverse is also true. Low levels produced at this time of night indicate there is no possible way you can have Cushing's syndrome (Cushing's Support and Research Foundation, 2009).

Cortisol Urine Test

• For proper results, a 24-hour urine test is needed. Therefore, on the day you intend to begin taking samples, you will need to get up and void in the toilet as you normally would. Every time you go to urinate after that, a specimen should be collected in a sterile container. The container should be capped tightly, clearly labeled and kept refrigerated until collection for the 24 hours is completed. The specimens should then be taken to the nearest laboratory where they can be evaluated (U.S. National Library of Medicine, 2009).

  Testing the cortisol levels on infants using the urine collection process is much more difficult. A urine collection bag is used and is fixed to the body of the infant. A diaper is then put on as usual over the bag. The bag should be checked often so it can be changed out for a new bag if there is already a specimen in it (U.S. National Library of Medicine, 2009).