Chronic pain is very common in all European countries, with musculoskeletal problems predominating. About 1% of the adult population develops a syndrome of chronic muscle pain, fibromyalgia (FMS), characterized by multiple tender points, back or neck pain, and a number of associated problems from other organs, including a high frequency of fatigue. Evidence points to central sensitization as an important neurophysiological aberration in the development of FMS. Importantly, these neurological changes may result from inadequately treated chronic focal pain problems such as osteoarthritis or myofascial pain. It is important for health professionals to be aware of this syndrome and to diagnose the patients to avoid a steady increase in diagnostic tests. On the other hand, patients with chronic widespread pain have an increased risk of developing malignancies, and new or changed symptoms should be diagnosed even in FMS. In rheumatology practice it is especially important to be aware of the existence of FMS in association with immune inflammatory diseases, most commonly lupus and rheumatoid arthritis. Differential diagnoses are other causes of chronic pain, e.g. thyroid disease. The costs of this syndrome are substantial due to loss of working capability and direct expenses of medication and health-system usage. Fibromyalgia patients need recognition of their pain syndrome if they are to comply with treatment. Lack of empathy and understanding by healthcare professionals often leads to patient frustration and inappropriate illness behavior, often associated with some exaggeration of symptoms in an effort to gain some legitimacy for their problem. FMS is multifaceted, and treatment consists of both medical interventions, with emphasis on agents acting on the central nervous system, and physical exercises.