Hi @suemer . I am currently working with a functional medicine doctor. He works on getting to the root cause of my illness. For example, I was having obvious low cortisol symptoms -- debilitating fatigue, salt cravings, increased thirst, hypoglycemia and more. The endocrinologist however simply looked at my blood work and since my cortisol was in the "normal" lab reference range, he dismissed me. A functional medicine doctor will look at the entire picture and take in to consideration optimal levels. My cortisol and other labs were NOT at optimal levels. Anyway, those issues are now being addressed and I am seeing improvements. I think there is a Functional Medicine Clinic that is part of the Cleveland Clinic. I am not sure about the Mayo Clinic though. I have been dealing with recurrent Epstein-Barr and Chronic Fatigue Syndrome. From what I understand, Mayo does not deal with those things. In fact, their website info is not even up to date with the CDC when it comes to CFS. I'm not sure if this is helpful. Hopefully others will chime in. I wish you the best in your healing journey.