One of the best examples of this is during ischemia brought on by a myocardial infarction (
heart attack) where pain is often felt
in the neck, left arm, shoulders, and back rather than in the chest, the site of the injury. The International Association for the Study of Pain, as of 2001, has not officially defined the term; hence several authors have defined the term differently.
Physicians and scientists have known about referred pain since the late 1880s.