The International Association for the Study of Pain (IASP) has defined pain as “an unpleasant sensory and emotional experience associated with ACTUAL or POTENTIAL tissue damage”.
Pain is personal, difficult for an outsider to understand fully, but it is not unusual—all of us have some understanding of pain. Each individual learns through experiences related to injury early in life.
Acute pain is usually adaptive and can alert us to something that is harmful.
Persistent pain is not adaptive. This may not indicate tissue damage, but it also triggers those psychological responses that have been learned at an early age and with past painful events.