Pain is defined by the International Association for the Study of Pain (IASP) as ‘an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage’.Most pain is short-lived, resolving when the painful stimulus is removed or when tissue healing has occurred: this is called acu...

The American Academy of Physical Medicine and Rehabilitation (AAPM&R): Physical medicine and Rehabilitation (PM&R) Knowledge Journal:True visceral pain is a physiologically and clinically separate entity from somatic pain.  Visceral pain responses are provoked by ischemia, inflammation, and distention. Visceral pain is poorly defined and diffu...