Fibromyalgia affects up to 2% of the population and can start at any age; it is at least 7 times more common in women than in men.(1) By the time the diagnosis is made, patients have often had symptoms for many years. Patients with fibromyalgia complain of pain all over and, by definition, have pain on both sides of the body, above and below the waist, and in both the trunk and extremities.(2)
Patients describe the pain in many different ways, often very emotionally. Muscular stiffness is a prominent complaint. Associated features include nonrestorative sleep, irritable bowel syndrome, headaches, paresthesias and a sensation of swelling of the hands and feet. Fibromyalgia is frequently associated with depression, memory and concentration difficulties, and anxiety, and it often accompanies other chronic painful disorders.
A diagnosis of fibromyalgia is made when there is widespread pain lasting for at least 3 months accompanied by tenderness at discrete locations (Fig. 1). Tender points are palpated with the thumb, using sufficient force to cause blanching of the nailbed. To be eligible for research studies, patients must have at least 11 tender points of a possible 18 but, in practice, the diagnosis can be made in patients with fewer tender points if there is widespread pain and many of the other characteristic symptoms.(3) Patients with fibromyalgia are often tender all over; the presence of tenderness other than at the classic locations does not exclude the diagnosis.