Editing Pain (section)

=== Asymbolia and insensitivity ===
{{Main|Pain asymbolia|Congenital insensitivity to pain}}
{{Redirect|Painless}}
[[File:No pain. Science Museum Painless Exhibition Series.webm|thumb|A patient and doctor discuss congenital insensitivity to pain.]]
The ability to experience pain is essential for protection from injury and recognition of the presence of injury. Episodic [[analgesia]] may occur under special circumstances, such as in the excitement of sport or war: a soldier on the battlefield may feel no pain for many hours from a traumatic amputation or other severe injury.<ref>{{cite book | vauthors = Beecher HK | date = 1959 | title = Measurement of subjective responses | url = https://archive.org/details/measurementofsub0000beec | url-access = registration | location = New York | publisher = Oxford University Press}} cited in {{cite book | vauthors = Melzack R, Wall PD | date = 1996 | title = The challenge of pain | edition = 2nd | location = London | publisher = Penguin | page = 7 | isbn = 978-0140256703}}</ref>

Although unpleasantness is an essential part of the [[International Association for the Study of Pain|IASP]] definition of pain,<ref name="IASPdef">{{cite web|title=International Association for the Study of Pain: Pain Definitions|url=https://www.iasp-pain.org/Taxonomy|url-status=dead|archive-url=https://web.archive.org/web/20150113000208/https://www.iasp-pain.org/Taxonomy|archive-date=13 January 2015|access-date=12 January 2015|quote=Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage}} [https://etc.ch/ZTKs Alt URL]{{Dead link|date=February 2022 |bot=InternetArchiveBot |fix-attempted=yes }} Derived from {{cite journal|vauthors=Bonica JJ|date=June 1979|title=The need of a taxonomy|journal=Pain|volume=6|issue=3|pages=247–248|doi=10.1016/0304-3959(79)90046-0|pmid=460931|s2cid=53161389}}</ref> it is possible in some patients to induce a state known as pain asymbolia, described as intense pain devoid of unpleasantness, with [[morphine]] injection or [[psychosurgery]].<ref name=IASP_definitions/> Such patients report pain but are not bothered by it; they recognize the sensation of pain but suffer little or not at all.<ref name="asymbolia">{{cite book | vauthors = Grahek N |title=Feeling pain and being in pain |date=2007 |publisher=MIT Press |location=Cambridge, Mass. |isbn=978-0262517324 |edition=2nd | url = https://docserver.bis.uni-oldenburg.de/publikationen/bisverlag/2001/grafee01/grafee01.html | archive-url = https://web.archive.org/web/20080927042509/https://docserver.bis.uni-oldenburg.de/publikationen/bisverlag/2001/grafee01/grafee01.html | archive-date = 27 September 2008 }}</ref> Indifference to pain can also rarely be present from birth; these people have normal nerves on medical investigations, and find pain unpleasant, but do not avoid repetition of the pain stimulus.<ref name="pmid12583863">{{cite journal | vauthors = Nagasako EM, Oaklander AL, Dworkin RH | title = Congenital insensitivity to pain: an update | journal = Pain | volume = 101 | issue = 3 | pages = 213–219 | date = February 2003 | pmid = 12583863 | doi = 10.1016/S0304-3959(02)00482-7 | s2cid = 206055264 }}</ref>

Insensitivity to pain may also result from abnormalities in the [[nervous system]]. This is usually the result of [[acquired disorder|acquired]] damage to the nerves, such as [[spinal cord injury]], [[diabetes mellitus]] ([[diabetic neuropathy]]), or [[leprosy]] in countries where that disease is prevalent.<ref name=Brand_1997>{{cite book | vauthors = Brand PW, Yancey P |title=The gift of pain: why we hurt & what we can do about it |publisher=Zondervan Publ |location=Grand Rapids, Mich |year=1997 |isbn=978-0310221449}}</ref> These individuals are at risk of tissue damage and infection due to undiscovered injuries. People with diabetes-related nerve damage, for instance, sustain poorly healing foot ulcers as a result of decreased sensation.<ref name="pmid15472838">{{cite journal | vauthors = Lipsky BA, Berendt AR, Deery HG, Embil JM, Joseph WS, Karchmer AW, LeFrock JL, Lew DP, Mader JT, Norden C, Tan JS | title = Diagnosis and treatment of diabetic foot infections | journal = Clinical Infectious Diseases | volume = 39 | issue = 7 | pages = 885–910 | date = October 2004 | pmid = 15472838 | doi = 10.1086/424846 | first11 = JS | first10 = C | doi-access = free }}</ref>

A much smaller number of people are insensitive to pain due to an inborn abnormality of the nervous system, known as "[[congenital insensitivity to pain]]".<ref name="pmid12583863"/> Children with this condition incur carelessly-repeated damage to their tongues, eyes, joints, skin, and muscles. Some die before adulthood, and others have a reduced life expectancy.<ref>{{Cite journal |last1=Raina* |first1=Triveni |last2=Dash |first2=Bhagya Ranjan |title=AN INTRODUCTORY APPROACH TO PAIN MANAGEMENT THROUGH AYURVEDA WITH BRIEF HOLISTIC REVIEW |url=https://core.ac.uk/outputs/333809971/?utm_source=pdf&utm_medium=banner&utm_campaign=pdf-decoration-v1 |archive-date=27 August 2024 |access-date=27 August 2024 |archive-url=https://web.archive.org/web/20240827103149/https://core.ac.uk/outputs/333809971/?utm_source=pdf&utm_medium=banner&utm_campaign=pdf-decoration-v1 |url-status=live }}</ref> Most people with congenital insensitivity to pain have one of five [[hereditary sensory and autonomic neuropathy|hereditary sensory and autonomic neuropathies]] (which includes [[familial dysautonomia]] and [[congenital insensitivity to pain with anhidrosis]]).<ref name=Axelrod>{{cite journal | vauthors = Axelrod FB, Hilz MJ | title = Inherited autonomic neuropathies | journal = Seminars in Neurology | volume = 23 | issue = 4 | pages = 381–390 | date = December 2003 | pmid = 15088259 | doi = 10.1055/s-2004-817722 | s2cid = 260317729 }}</ref> These conditions feature decreased sensitivity to pain together with other neurological abnormalities, particularly of the [[autonomic nervous system]].<ref name="pmid12583863"/><ref name=Axelrod/> A very rare syndrome with isolated congenital insensitivity to pain has been linked with mutations in the ''[[SCN9A]]'' gene, which codes for a sodium channel ([[Nav1.7|Na<sub>v</sub>1.7]]) necessary in conducting pain nerve stimuli.<ref name="pmid21041956">{{cite journal | vauthors = Raouf R, Quick K, Wood JN | title = Pain as a channelopathy | journal = The Journal of Clinical Investigation | volume = 120 | issue = 11 | pages = 3745–3752 | date = November 2010 | pmid = 21041956 | pmc = 2965577 | doi = 10.1172/JCI43158 }}</ref>