I have been being treated with 175mcg synthroid for the last 3 months, and my doctor says my TSH is in a normal range at 2.53. My pulse goes from normal to bounding, I stay tired, can't sleep, and now I am starting to bruise easily. The doctor says the knots in my throat are submandibular glands not my thyroid, and is sending me to a caerdiologist because he feels I have an infection somewhere, and as I have 3 stents (no personal history of heart disease, just some narrowing in the major arteries in the heart), he feels I need to see a heart doctor. I feel strongly that it is somehow related to the endocrine system. What can it be? I have a sister whose thyroid, pancreas, and adrenal glands are not working, and I do not want to get into the same shape. Can I have hyper-thyroid symptoms with a normal thyroid level, and if so what can cause it????