If it's the thyroid, as Dahlek mentioned, make sure they get both a T3 (Triiodothyronine) and T4 (thyroxine) levels done, a TSH level, as well as a TBG and TBPA (thyroxine-binding globulin and thyroxine-binding prealbumin). There are literally 100s of different hormones at work in your body, so its hard to say which ones.

People with chronic pain issues can often be "out of whack" from the constant stress the body is under, which in turn can cause any one of a number of endocrine issues, from adrenal disorders to extremely low levels of testosterone. Good luck at your appointment and I hope you get some answers soon.

Theresa