Musculoskeletal pain is common in the population. Several pathologies like fibromyalgia (FM), chronic fatigue syndrome (CFS) or spasmophilia are associated with functional myalgia. The etiology of FM remains elusive, but the diagnosis is well established. The criteria for the classification are widespread pain combined with tenderness at 11 or more of the 18 specific tender points sites. The prevalence is 2% in the general population. This article reviews recent data on the pathophysiology and treatment of FM.