Physiology, Pain

Pain is likely the most common symptomatic complaint in medicine; an understanding of its pathophysiology is critical to interpreting it in patients.

Differentiating between the terms nociception and pain is worthwhile. Nociception refers to the detection of noxious stimuli by nociceptors, followed by transduction and transmission of the sensory nervous information from the periphery to the brain. In comparison, pain refers to the product of higher brain center processing; it entails the actual unpleasant emotional and sensory experience generated from nervous signals. Reports of pain are thus not merely a direct output of nociception, they involve interaction with numerous inputs (attention, affective dimensions, autonomic variables, immune variables and more), and may be considered more accurately from the perspective of a neuromatrix.