[Fibromyalgia syndrome, a frequently misdiagnosed entity].

Fibromyalgia syndrome is a frequent condition. It mainly affects middle-aged women, who complain of diffuse pain in the proximal limb girdles and trunk, morning stiffness, unrefreshing sleep, tiredness, and fear, without abnormal physical findings on examination. This review considers the currently evaluated diagnostic criteria and recent research data, which suggest that fibromyalgia in fact is most probably primarily a brain disturbance involving neurohormonal abnormalities and impaired deep sleep. Effective and ineffective therapies are discussed.