Doctors tend to recommend a one-time blood test or an ACTH STIM test, but patients have found both to be inadequate measures to discern sluggish adrenals. The ACTH will tell you how much stimulation your adrenals are getting, but not how much cortisol they are producing. Instead, we have relied on the 24 hour adrenal saliva test, which tests your cortisol levels at four different times of day and allows you to view your daily cyclic adrenal function. (And note that if you are very hypothyroid, you readings may actually be even lower than your saliva results will show, since being hypothyroid results in a slower clearance of cortisol from your body.) You can get information about the test and the price from www.NPTech.com