1. Do I need both tests (blood and urine) or is one better than the other?
If your doctor suspects Cushing's syndrome, usually both blood and urine are tested. Blood cortisol is easier to collect but is affected more by stress than is the urine test. Salivary cortisol may sometimes be tested instead of blood cortisol.
2. How do I tell if a high cortisol level isn’t just from stress?
There are several approaches that your doctor can take. The simplest involves repeating tests at a time when you feel less stressed. Your doctor can also give you varying doses of a medicine that replaces cortisol (usually dexamethasone) to see if this decreases your cortisol level. Multiple tests are often needed to tell if stress or disease is causing a high cortisol level.
