All your hormones are part of your endocrine system so one sees an endocrinologist:

http://www.hormone.org/public/endocrinologist.cfm

I have an incidentaloma (lump in my adrenal gland) they discovered when my appendix burst and they were doing the CT scan to figure that out. So I later (after the appendix thing was thought to be under control) had to take various texts and then go to an endocrinologist and see if it was a problem/cancer or not; have him read the results and advise me. It's a really complicated system.

I told this doctor about my incidentaloma (and it was a little frightening because he had no clue what that was but when I explained, called it an adrenaloma, which will do) and he immediately had me take a couple tests to see if that situation might have changed and thus be the problem instead of my thyroid but all was well there. It's called an incidentaloma because back before CT/MRI's, etc. people's weren't found until after they died of regular old age, in autopsies; they were only "incidentally" found. They just sit there and don't change and it's not known where they come from but they're not cancerous.

I think Hashimotos always progresses to bad news doesn't it? I know what you mean about figuring things out for yourself though; my busted appendix, I had a bad reaction to one of the antibiotics so had an infection wandering around for 5 months and my surgeon wanted to operate again but I made him try another, different kind of antibiotic I'd found on the Web and that worked and I was finally well/fine. My little $3,000-$5,000 appendectomy only cost the insurance company/us $35,000-$40,000 by the time I was finally better (was in the hospital for a week on intervenous antibiotics, still the "wrong" kind and had all sorts of other tests and things inbetween).