Hi, I'm a 48 year old white female. I had a complete thyroidectomy when I was 29 and have been taking levothyroxine 88mcg for many years - my levels are pretty steady. In the last couple of months I have gained about 20 pounds, feel tired all the time and have muscle/joint aches to the point to where it hurts to just get up from sitting position or if sitting too long it begins to hurt. I had my TSH and free T4 levels checked a couple of months ago and within normal limits. I keep telling myself its just part of getting older but really becoming concerned...do I have reason to be concerned?