The fibromyalgia syndrome: musculoskeletal pathophysiology.

Fibromyalgia (FM) is a chronic pain disorder that afflicts predominantly middle-aged women with cardinal symptoms of diffuse musculoskeletal pain, defined tender points, deprived sleep, and fatigue. The etiology and pathological mechanisms are poorly understood, and treatment approaches are largely ineffective. The clinical features of the syndrome are presented, and the relevance of muscle dysfunction in the etiopathogenesis of the disorder is explored. The evidence for involvement of muscle pathophysiology as a primary mechanism mediating the onset of symptoms is not compelling. Musculoskeletal dysfunction can be considered secondary to central abnormalities of pain modulation and altered sleep physiology precipitated by emotional stress in genetically predisposed individuals. Contemporary evidence favors treatment strategies that emphasize pain control, sleep enhancement, and a program of conditioning.