Doctor wants to do tests to see if I have cushing syndrome?

OK, do it. Cushing's syndrome is a condition where your body makes too much cortisol (a hormone). A blood draw or 24 hour urine measurement of cortisol will give you the diagnosis. Another test called dexamathasone suppression test will also give you the diagnosis. Often time, you will need to repeat the tests, or do all of them. It's probably the most difficult diagnosis to make in endocrinology.