Chronic widespread pain: from peripheral to central evolution.

Chronic pain can be classified as localised, regional or widespread, and its high prevalence in the general population seems to increase with age. The majority of cases present with musculoskeletal pain. The conditions associated with chronic widespread pain (CWP) are highly burdensome as their characteristic symptoms may include multifocal pain, fatigue, insomnia, memory difficulties and a higher rate of concomitant mood disorders. After many years of debate, it is still unclear whether CWP (central sensitisation) is an entirely explainable neurotransmitter-related process or is partially or totally due to individual cognitive experiences and evaluations. The two models (neurochemical and biopsychosocial) also affect our ability to find therapeutic answers.