Fibromyalgia syndrome (FMS) is a very common condition of widespread musculoskeletal pain, fatigue and multiple tender points. Fibromyalgia means pain in the muscles, ligaments and tendons--the fibrous tissues in the body. FMS used to be called fibrositis, implying that there was inflammation in the muscles, but research later proved that inflammation did not exist. People with this syndrome may also experience disturbances of sleep, and varying degrees of anxiety and depression related to the changed physical status. Furthermore, certain other medical conditions are commonly associated with fibromyalgia, such as: tension headaches, migraine, irritable bowel syndrome, irritable bladder syndrome, premenstrual tension syndrome, sensitivity to cold, memory and concentration difficulties and restless leg syndrome. More women than men are afflicted with fibromyalgia, but it shows up in people of all ages. Although the cause is unknown and diagnosis can be difficult (because many of the symptoms mimic those of other disorders), researchers have several theories about causes or triggers of the syndrome. One of the most frustrating aspects of fibromyalgia is that others cannot see or feel the magnitude of the pain you are experiencing. People may remark about how well you look, but this can be distressingly inconsistent with how terrible you feel. Because fibromyalgia produces few symptoms that are outwardly noticeable, it has been nicknamed "the invisible disability". There is currently no generally accepted cure for this condition. However, most patients may benefit from a combination of exercise, medication, physical therapy and relaxation.