I had thyroid cancer about 34 years and had my entire thyroid removed and was on Tertroxine then changed to Thyroxine, currently 125mcg daily. For years I've had muscle issues, mostly cramping but getting progressively worse. I even had to stop a yoga class due to cramping and muscle spasms during the class. I'm 58 though look much younger but feel like an old lady with aches and stiffness. I also feel my memory is terrible and worry I'm getting early dementia. These issues have prompted me to see my GP next week as after doing some thinking and researching I feel Levothyroxine may be the common denominator and I've read some of the posts here which convinces me more. People complain of muscle pain and stiffness but I get frequent and excruciating cramps then tenderness and tightness/stiffness which started in my legs but now affecting other parts of my body. There are other lesser problems which may or may not be connected. Fingers crossed I can get this sorted out. I've been worrying what is causing this thinking I've got some muscle wasting disease but think I'm on the right track. My GP is pretty good so think she will be supportive. I'm going to keep reading through the posts here and any responses will be appreciated.