Pain

There have been many attempts to classify and define pain, and discussions about the nature of pain versus nociception.^{[Kumar & Elavarasi, 2016; Treede, 2018]} In 1979, the International Association for the Study of Pain (IASP) defined pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”.^{[Merskey et al., 1979]} Subsequent attempts have been made to reach a more exacting definition, including by introducing elements of the individual’s perception and interpretation of the feeling of pain.^{[Kumar & Elavarasi, 2016; Cohen et al., 2018]}

A distinction is sometimes drawn between pain and nociception: pain is a subjective experience,^{[Kumar & Elavarasi, 2016]} whereas nociception is the process within the nervous system that responds to the noxious stimuli.^{[Treede, 2018]} In this sense, pain is from the first-person perspective, whilst nociception is from the third-person perspective.^{[Treede, 2018]}

References:
Cohen M, Quintner J, van Rysewyk S. Reconsidering the International Association for the Study of Pain definition of pain. Pain Rep 2018; 3 (2): e634.

Kumar KH, Elavarasi P. Definition of pain and classification of pain disorders. J Adv Clin Res Insight 2016; 3 (3): 87–90.

Merskey H, Albe Fessard D, Bonica JJ, et al. Pain terms: a list with definitions and notes on usage. Recommended by the IASP subcommittee on taxonomy. PAIN 1979; 6: 249–252.

Treede RD. The International Association for the Study of Pain definition of pain: as valid in 2018 as in 1979, but in need of regularly updated footnotes. Pain Rep 2018; 3 (2): e643.

Other references used on slide:
Steeds CE. The anatomy and physiology of pain. Surgery 2016; 34 (2): 55–59.

Urch C. Normal pain transmission. Rev Pain 2007; 1 (1): 2–6.