Referred pain from somatic and visceral structures

Abstract

The term “referred pain” is used for pain localized not in the site of its origin but in areas that may be adjacent or at a distance from such a site, generally comprised in the same metameres. Pain can be referred by deep somatic or by visceral structures. Myofascial pain syndrome is a typical syndrome characterized by referred pain from deep somatic structures. Referred pain from visceral organs is the most important from a clinical point of view. The patterns of referred pain orginating from various viscera are important for a correct diagnosis. Different pathogenetic mechanisms may be involved in the onset of referred pain: convergence of impulses in the central nervous system and reflexes inducing muscle contraction, sympathetic activation, and antidromic activation of afferent fibers, which induces socalled “neurogenic inflammation”.