Clinical Pathophysiology and Anatomy of Acute Pain

According to the definition of the International Association for the Study of Pain, hyperalgesia means "an excessive reaction to moderate nociceptive stimulation". Primary hyperalgesia or peripheral sensitization is a reflection of activation and sensitization of nociceptive A-delta fibers and terminal windows of polymodal C-fibers in injured tissues. The basis of secondary hyperalgesia or central sensitization is spinal neuroplasticity and facilitating the transfer of nociceptive information to supraspinal structures.