Pain

Pain is the unpleasant feeling common to such experiences as stubbing a toe, burning a finger, placing iodine on a cut and bumping the "funny bone".^[1] The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage".^[2] Pain motivates us to withdraw from damaging or potentially damaging situations, protect the damaged body part while it heals, and avoid those situations in the future.^[3]

Virtual reality hypnotism (computer simulation) shows significant pain reduction for patients suffering burns or spinal cord injury and 50% reduction in medication (Askay, Patterson & Sharar, 2009).

Askay, S. W., Patterson. D. R.., & Sharar, S. R. (2009). Virtual reality hypnosis. Contemporary Hypnosis, 26 (1), 40-47.

1. ↑ The examples represent respectively the three classes of nociceptive pain - mechanical, thermal and chemical - and neuropathic pain.
2. ↑ "IASP definition, full entry". Retrieved 6 October 2009. This often quoted definition was first formulated by an IASP Subcommittee on Taxonomy:
   Bonica, JJ (1979). Pain 6 (3): 247–252. ISSN 0304-3959. PMID 460931. 
   It is derived from Harold Merskey's 1964 definition: "An unpleasant experience that we primarily associate with tissue damage or describe in terms of tissue damage or both."
   Merskey, H (1964). An Investigation of pain in psychological illness, DM Thesis. Oxford University. 
3. ↑ Lynn, B (1984). "Cutaneous nociceptors". In Holden, AV; Winlow, W. The neurobiology of pain. Manchester, UK: Manchester University Press. p. 106. ISBN 0-7190-0996-0. http://books.google.com.au/books?id=S7rnAAAAIAAJ&pg=PA106&dq=%22behaviour+designed+to+protect+the+affected+part%22&lr=&client=firefox-a&cd=1#v=onepage&q=%22behaviour%20designed%20to%20protect%20the%20affected%20part%22&f=true.