According to the IASP (International Association for the Study of Pain) descriptions of pain terms, pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or is described in terms of such damage. Pain is classified as acute and chronic, or nociceptive and non-nociceptive pain. Acute pain is elicited by the injury of the body tissues and activation of nociceptive transducers at the site of local tissue damage. Chronic pain is usually elicited by an injury but may be perpetuated by factors that are both pathogenically and physically remote from the original cause. This type of pain frequently prompts patients to seek health care, and is rarely treated effectively. Nociceptive pain is initiated by noxious stimuli, whereas neuropathic pain is initiated or caused by a primary lesion, a dysfunction in the nervous system. Psychogenic pain is the report of pain attributable primarily to psychological factors, usually in the absence of any objective physical pathology that could account for pain. (J Korean Assoc Pain Med 2002;1:1-3)

KeywordsPain, Definition, Classification, Nociceptive, Psychogenic