Persistent Pain: A Disease Entity

Persistent pain is a common condition that is both disabling and costly, yet it is often managed inadequately. Suboptimal treatment may result, at least in part, from the lack of recognition of persistent pain as a disease entity; that is, a condition having its own specific cause, signs, and symptoms. This brief review presents evidence of independent, pain-perpetuating pathophysiologic changes that occur after, or in the absence of, acute painful events or concomitant painful conditions. Such changes occur throughout the nervous system (periphery, spinal cord, and brain) and contribute to altered responses to innocuous stimuli (allodynia) and noxious stimuli (hyperalgesia). Both internal and external environmental factors (e.g., genetic predisposition, psychologic conditions, and social interactions) also likely influence individual pain experiences. The acceptance of persistent pain as a disease entity is an important first step in the search for improved management strategies that specifically target distinct pain pathology.