How does referred pain cause pain from internal organs to be felt on the body surface?

Referred pain occurs when pain originating in internal organs is perceived in somatic tissues, such as the skin or body wall. This phenomenon is primarily attributed to the anatomical convergence of nerve fibers within the spinal cord.12

Specifically, afferent nerve fibers from visceral organs and those from somatic tissues (like the skin and muscles) often synapse onto the same neurons in the dorsal horns of the spinal cord. Because the brain is accustomed to receiving sensory input primarily from the skin and body wall—which have a much larger representation in the sensory cortex compared to the relatively unused visceral representation—it interprets the incoming visceral signals as originating from the more familiar somatic regions.12

While this convergence is a key factor, it does not fully explain the false localization on its own; it is likely that the brain’s limited experience in processing visceral pain leads it to misidentify the source, projecting the sensation to the body surface instead.1