I have been treated with levothyroxine for approximately 20 years. I am now expieriencing leg weakness and pain when walking standing or sleeping(both),low back pain, low grade temps and fatigue. I have had lymph nodes swelling in the past, but ulrasounds showed nothing. My Md has suggested I walk more to build leg muscles, when i tried walking 6 blocks, i came home and needed to take motrin just to bear the discomfort. Any suggestion would be greatly appreciated. Thank you