Fibromyalgia is a chronic condition that causes pain, stiffness, and tenderness of the muscles, tendons, and joints. Fibromyalgia is also characterized by restless sleep, awakening feeling tired, chronic fatigue, anxiety, depression, and disturbances in bowel function. Fibromyalgia is sometimes referred to as fibromyalgia syndrome and abbreviated FMS. The cause of fibromyalgia is not known. The universal symptom of fibromyalgia is pain. As mentioned earlier, the pain in fibromyalgia is not caused by tissue inflammation. Instead, these patients seem to have an increased sensitivity to many different sensory stimuli and an unusually low pain threshold. Minor sensory stimuli that ordinarily would not cause pain in individuals can cause disabling, sometimes severe pain in patients with fibromyalgia. The body pain of fibromyalgia can be aggravated by noise, weather change, and emotional stress. The diagnosis of fibromyalgia is made purely on clinical grounds based on the doctor s history and physical examination. Treatment programs are most effective when they combine patient education, stress reduction, regular exercise, and medications.