Fibromyalgia is a chronic and widespread musculoskeletal pain syndrome, the hallmarks of which are tenderness, amplified pain, and severe fatigue. Though it is similar to arthritis, fibromyalgia does not cause the same inflammation. People who have fibromyalgia often experience stiff joints, headaches, and depression. Similar to fibromyalgia, myofascial pain syndrome can cause widespread musculoskeletal pain; however, it is treated differently.