Fibromyalgia (FM) is a isorder classified by the presence of chronic widespread pain and tactile allodynia. While the criteria for such an entity have not yet been thoroughly developed, the recognition that fibromyalgia involves more than just pain has led to the frequent use of the term "fibromyalgia syndrome". It is not contagious, and recent studies suggest that people with fibromyalgia may be genetically predisposed. The disorder is not directly life-threatening. The degree of symptoms may vary greatly from day to day with periods of flares (severe worsening of symptoms) or remission; however, the disorder is generally perceived as non-progressive.