30 Thyroid Symptoms That Are Too Important to Ignore

24. Muscle Soreness, Pain, and Stiffness

Muscle pain isn't just for the gym. When your thyroid is out of balance, you might notice your muscles feeling sore, tired, or heavy. This happens because your metabolism slows down, and your body starts breaking down muscle tissue to generate energy. This process, called catabolism, can leave you feeling achy and stiff.