Definition, classification and critical review of the most influential theories of pain from the past to the present

The origin of the concept of pain dates back to ancient times, which has been the subject of debate since then. Since 1800 AD, according to the development of experimental sciences, various theories of pain based on experimental evidence have been formed. However, existing theories of pain may be suitable for explaining some aspects of pain, but none of them had fully explained all aspects of pain perception.

In the current study, the definition of pain, and its types and classification of were investigated. Then, the traditional theories of pain, such as specific theory, Pattern theory, gate control theory, and their evolution of were examined. Also, the most influential bio-psychosocial theories which formed the basis of research and interventions in the field of pain were considered. Ultimately, biological theories and the latest achievements in chronic and acute pain have been reviewed.

Until now, none of the theories of pain covers all aspects of pain, so in order to better understand pain with the aim of health policies, research and treatment, it is necessary to address different theories of pain.