Fibromyalgia syndrome: presentation, diagnosis, differential diagnosis, and vulnerability.

Fibromyalgia syndrome (FMS) presents with widespread soft tissue pain. Common comorbidities include severe insomnia, body stiffness, affective symptoms, irritable bowels, and urethral syndrome. A 1990 research classification depends on a history of widespread pain and prominent tenderness to palpation at 11 or more of 18 specific tender points. It is a criteria-based diagnosis rather than one by exclusion and can accompany other medical conditions. FMS occurs worldwide, and can present any age, but is most common in adult females. Although numerous studies and reviews contend that FMS may be caused by psychological stress such as sexual abuse, critical epidemiological review fails to support that concept. Existing data suggest that some individuals with FMS may have a dysregulated physiological stress response system that predates the onset of symptoms.