While not generally well-known or understood, hypothyroidism and hyperthyroidism can cause a variety of muscle or joint-related symptoms. Skeletal muscles are the muscles connected to your bones. An example of a skeletal muscle is your biceps in the upper arm, or the quadriceps in the thigh. Myopathies most often are seen in what are known as the in joint muscle pain muscles.
These are the muscles, such as in the thigh and shoulder area, that are closest to the center of the body. In myopathies caused by inflammation or metabolic conditions, such as autoimmune thyroid disease, white blood cells may attack parts of the muscle and the surrounding blood vessels, or abnormal levels of certain biochemical substances end up accumulating in your muscles, leading to weakness or pain. Different thyroid conditions can also be associated with particular types of muscle and joint problems. Hypothyroidism can create a variety of muscle and joint-related symptoms.