Given the description of symptoms you gave in your letter and treatment of your condition with Synthroid, I must presume that you are getting this medicine for lower function of the thyroid gland. Synthroid is a supplement of a thyroid hormone used to threat hypothyroidism, when the thyroid gland does not produce enough thyroid hormone. You have mentioned parathyroid gland removal last December. It is of a great importance to make regular tests for the function of both glands, thyroid and parathyroid. Symptoms such as hot flushes, muscle and joint pain, stomach pain, nausea, severe fatigue, depression or anxiety, constipation, overall swelling and hot flushes, are related symptoms of hypothyreosis.Sometimes, menopause can cause the same problems. So, you may consult your gynecologist as well.