Walsh & Hoyt: Pain Terminology

Before discussing the pathways involved in processing pain, and the variety of pain syndromes, it is helpful to review some of the terminology used in pain literature. Referred pain is pain in an area far removed from the site of tissue injury. Phantom pain refers to pain in a part of the body that has been surgically removed or is congenitally absent. Allodynia is a nonnoxious stimulus that is perceived as painful (e.g., light touch producing pain). Sensitization occurs when a receptor responds to a stimulus in a more intense fashion than expected, or to a stimulus to which it would not normally respond. Hyperalgesia is exacerbated pain produced by a noxious stimulus (e.g., mild pinprick causing severe pain out of proportion to the stimulus). Hyperpathia refers to intense pain with repetitive stimuli. Anesthesia refers to complete loss of sensation. Paresthesias are abnormal sensations, such as burning, tingling, or formication, that are not typically painful. A nociceptor is a nervous system receptor capable of distinguishing between a noxious and innocuous stimulus.