Anatomy & Physiology: Current Research
Open Access

Abstract

Anatomical and Physiological Basis of Chronic Pain Mechanisms

Nurul Aisyah Rahman

Chronic pain is a major global health concern that affects hundreds of millions of individuals and represents one of the leading causes of disability and reduced quality of life. Unlike acute pain, which serves as a protective physiological response to tissue injury, chronic pain persists beyond the normal healing period and often becomes a disease in its own right. Advances in anatomy, neurophysiology, molecular biology and pain neuroscience have substantially improved our understanding of the complex mechanisms underlying chronic pain. Rather than resulting solely from damaged tissues, chronic pain is now recognized as a multidimensional condition involving intricate interactions among peripheral nerves, the spinal cord, the brain, immune cells and the musculoskeletal system. These emerging insights are reshaping both pain research and clinical management. The anatomical foundation of pain begins with specialized sensory receptors known as nociceptors. These free nerve endings are widely distributed throughout the skin, muscles, joints, fascia, periosteum and visceral organs. Nociceptors detect potentially harmful mechanical, thermal, or chemical stimuli and transmit signals through A δ and C nerve fibers to the dorsal horn of the spinal cord. Under normal physiological conditions, this pathway enables rapid detection of injury and initiates protective reflexes. However, persistent activation of nociceptors following tissue damage or inflammation can alter neural function, contributing to the transition from acute to chronic pain

Published Date: 2025-08-04; Received Date: 2025-07-04