Physiology and pathophysiology of chronic pain (Part I)

Abstract

Chronic pain imposes a significant health burden on society and has a debilitating impact on individuals and their productivity.1 Chronic pain has been reported to affect 20% of people worldwide.2 With the current world population at 7.8 billion, it is estimated that approximately 1.5 billion people suffer from chronic pain. The socioeconomic burden of chronic pain in the USA is between US$560 and US$635 billion annually.3 The impact of chronic pain in Africa is also worrisome: Nigeria has a prevalence 5.5%,4 while approximately 1 in 5 South Africans (18.3%) has been reported to suffer from chronic pain.5