[The pain epidemiology].

Acute pain is the most common symptom for which patients seek medical care. Chronic pain is severe and frequent health care problem in terms of patient suffering and economic implications for the society. More than half of chronic pain related to musculoskeletal pain. Epidemiological studies on pain are limited by inconsistencies in definition, identification, and evaluation. The reported prevalence ranges from 8 to 80%. A World Health Organization Study in Primary Care showed persistent pain in 22% of primary care patients and Survey of chronic pain in Europe showed chronic pain in 19%. Because, the large variation in frequency and the inconsistent relationship between persistent pain and disability we need to consider the global concept of chronic pain with implications for management and prognosis. Epidemiological research should have as goal the development effective healthcare interventions through better understanding of pain, impact on the individual and society.