{{for|the album by Bright Eyes|Motion Sickness}}

{{Infobox_Disease |

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DiseasesDB = 11908 |

ICD10 = {{ICD10|T|75|3|t|66}} |

ICD9 = {{ICD9|994.6}} |

ICDO = |

OMIM = 158280 |

MedlinePlus = |

eMedicineSubj = |

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MeshID = D009041 |

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'''Motion sickness''' or '''kinetosis''' is a condition in which a disagreement exists between visually perceived movement and the [[vestibular system]]'s sense of movement. Depending on the cause it can also be referred to as [[seasickness]], carsickness, simulation sickness, [[airsickness]], or [[Space adaptation syndrome|space sickness]].<ref name=benson>{{cite book |author=Benson AJ |title=Motion Sickness. In: Medical Aspects of Harsh Environments |volume=2 |chapter=35 |location=Borden Institute |place=Washington, DC |date=[[2002]] |url=http://www.bordeninstitute.army.mil/published_volumes/harshEnv2/harshEnv2.html |accessdate=2008-05-09 }}</ref>

[[Dizziness]], [[Fatigue (medical)|fatigue]], and [[nausea]] are the most common [[symptom]]s of motion sickness.<ref>[http://healthlink.mcw.edu/article/907367055.html Motion Sickness Prevention and Treatment]</ref> [[Sopite syndrome]] is also a side effect of motion sickness. In fact, ''nausea'' in [[Greek language|Greek]] means seasickness (''naus'' means ship).<ref> [http://colet.uchicago.edu/cgi-bin/chuck/woodhouse_pages.pl?page_num=745 Woodhouse's English-Greek Dictionary Page 745]</ref><ref>[http://colet.uchicago.edu/cgi-bin/chuck/woodhouse_pages.pl?page_num=766 Woodhouse's English-Greek Dictionary Page 766]</ref> If the motion causing nausea is not resolved, the sufferer will frequently [[vomit]]. Unlike ordinary sickness, vomiting in motion sickness tends not to relieve the nausea.<ref name=benson/>

About 33% of people are susceptible to motion sickness even in mild circumstances such as being on a boat in calm water, although nearly 66% of people are susceptible in more severe conditions.<ref name=benson/><ref>[http://www.pctoday.com/editorial/article.asp?article=articles/2006/t0405/33t05/33t05.asp&guid= PC Today Article - Motion Sickness]</ref>

Approximately 50% of the [[astronaut]]s in the U.S. space program have suffered from space sickness.<ref>[http://www.theshorthorn.com/archive/2003/spring/03-feb-18/n180203-02.html The Shorthorn Online | NEWS | Speech dispels space myths]</ref> Individuals and animals without a functional [[vestibular system]] are immune to motion sickness.<ref name="GMO">[http://www.brooksidepress.org/Products/OperationalMedicine/DATA/operationalmed/Manuals/GMOManual/clinical/Motion%20sickness.html General Medical Officer (GMO) Manual: Clinical Section: Motion Sickness<!-- Bot generated title -->]</ref>

Motion sickness on the [[sea]] can result from being in the [[berth]] of a rolling boat without being able to see the [[horizon]]. Sudden jerky movements tend to be worse for provoking motion sickness than slower smooth ones, because they disrupt the fluid balance more.<ref name=benson/> A "corkscrewing" boat will upset more people than one that is gliding smoothly across the oncoming waves. Cars driving rapidly around winding roads or up and down a series of hills will upset more people than cars that are moving over smooth, straight roads. Looking down into one's lap to consult a map or attempting to read a book while a passenger in a car may also bring on motion sickness.

The most common hypothesis for the cause of motion sickness is that it functions as a defense mechanism against [[neurotoxin]]s.<ref name="GMO"/> The [[area postrema]] in the [[human brain|brain]] is responsible for inducing vomiting when poisons are detected, and for resolving conflicts between vision and balance. When feeling motion but not seeing it (for example, in a ship with no windows), the [[inner ear]] transmits to the brain that it senses motion, but the eyes tell the brain that everything is still. As a result of the disconcordance, the brain will come to the conclusion that one of them is [[hallucinating]] and further conclude that the hallucination is due to poison ingestion. The [[brain]] responds by inducing vomiting, to clear the supposed toxin.

==Kinds==

===Airsickness===

{{main|Airsickness}}

''Airsickness'' is a sensation which is induced by air travel.<ref name=benson/> It is a specific form of motion sickness, and is considered a normal response in healthy individuals. Airsickness occurs when the [[central nervous system]] receives conflicting messages from the body (including the [[inner ear]], [[eye]]s and [[muscle]]s) affecting [[balance]] and [[Equilibrioception|equilibrium]].

===Sea-sickness===

{{main|Sea-sickness}}

''Seasickness'' is a form of motion sickness characterized by a feeling of [[nausea]] and, in extreme cases, [[Vertigo (medical)|vertigo]] experienced after spending time on a craft on [[water]].<ref name=benson/> It is typically brought on by the rocking motion of the craft<ref>{{cite journal |author=Gahlinger PM |title=A comparison of motion sickness remedies in severe sea conditions |journal=Wilderness Environ Med |volume=11 |issue=2 |pages=136–7 |year=[[2000]] |pmid=10921365}}</ref> or movement while immersed in water.<ref>{{cite journal |author=Norfleet WT, Peterson RE, Hamilton RW, Olstad CS |title=Susceptibility of divers in open water to motion sickness |journal=Undersea Biomed Res |volume=19 |issue=1 |pages=41–7 |year=[[1992]] |month=January |pmid=1536062 |url=http://archive.rubicon-foundation.org/2621 |accessdate=2008-05-09}}</ref>

===Simulation sickness===

''Simulation sickness'', or simulator sickness, is a condition where a person exhibits symptoms similar to motion sickness caused by playing computer/simulation/video games.<ref name=benson/>

The most common theory for the cause of simulation sickness is that the illusion of motion created by the virtual world, combined with the absence of motion detected by the inner ear, causes the [[area postrema]] in the [[brain]] to infer that one is hallucinating and further conclude that the hallucination is due to poison ingestion. The brain responds by inducing nausea and mass vomiting, to clear the supposed toxin.<ref name="GMO" /> According to this theory, simulation sickness is just another form of motion sickness.

The symptoms are often described as quite similar to that of motion sickness. Some can range from headache, drowsiness, nausea, dizziness, vomiting and sweating. A research done at the [[University of Minnesota]] had students play [[Halo (series)|Halo]] for less than an hour, and found that up to 50 percent felt sick afterwards.<ref>[http://www.kvbc.com/Global/story.asp?s=4867083 Could video games be making your kids sick?]</ref>

In a study conducted by U.S. Army Research Institute for the Behavioral and Social Sciences in a report published May 1995 titled "Technical Report 1027 - Simulator Sickness in Virtual Environments", out of 742 pilot exposures from 11 military flight simulators, "approximately half of the pilots (334) reported post-effects of some kind: 250 (34%) reported that symptoms dissipated in less than 1 hour, 44 (6%) reported that symptoms lasted longer than 4 hours, and 28 (4%) reported that symptoms lasted longer than 6 hours. There were also 4 (1%) reported cases of spontaneously occurring flashbacks".<ref>[http://www.cyberedge.com/info_r_a+p05_ss-es.html CyberEdge Information Services: Health & Safety, Simulator Sickness in Virtual Environments: Executive Summary]</ref><ref>[http://www.gamingillustrated.com/video_game_sickness.php Video Game Simulator Sickness]</ref>

===Space sickness===

{{main|Space adaptation syndrome}}

''Space sickness'' was effectively unknown during the earliest spaceflights, as these were undertaken in very cramped conditions; it seems to be aggravated by being able to freely move around, and so is more common in larger spacecraft.<ref name=benson/> Around 60% of all [[Space Shuttle]] astronauts currently experience it on their first flight; the first case is now suspected to be [[Gherman Titov]], in August 1961 onboard ''[[Vostok 2]]'', who reported dizziness and nausea. However, the first significant cases were in early Apollo flights; [[Frank Borman]] on ''[[Apollo 8]]'' and [[Rusty Schweickart]] on ''[[Apollo 9]]''. Both experienced identifiable and reasonably severe symptoms—in the latter case causing the mission plan to be modified.

== Treatment ==

Many cures and preventatives for motion sickness have been proposed.

=== Natural ===

One common suggestion is to simply look out of the window of the moving vehicle and to gaze toward the horizon in the direction of travel. This helps to re-orient the inner [[sense of balance]] by providing a visual reaffirmation of motion.{{Fact|date=February 2008}}

In the night, or in a ship without windows, it is helpful to simply close one's eyes, or if possible, take a nap. This resolves the input conflict between the eyes and the inner ear. Napping also helps prevent psychogenic effects (i.e. the effect of sickness being magnified by thinking about it).

Fresh, cool air can also relieve motion sickness slightly, although it is likely this is related to avoiding foul odors which can worsen nausea. <ref>[http://www.leftseat.com/AME/motion.htm FAA Medical Certification / Alcohol / Substance / Drugs - Motion Sickness]</ref>

=== Chemical ===

Over-the-counter and prescription medications are readily available, such as Dramamine ([[dimenhydrinate]])<ref>{{cite journal |author=Weinstein SE, Stern RM |title=Comparison of marezine and dramamine in preventing symptoms of motion sickness |journal=Aviat Space Environ Med |volume=68 |issue=10 |pages=890–4 |year=[[1997]] |month=October |pmid=9327113 }}</ref>, Stugeron ([[cinnarizine]]) and Bonine/Antivert ([[meclizine]]).

[[Scopolamine]] is effective<ref name="pmid17636710">{{cite journal |author=Spinks A, Wasiak J, Villanueva E, Bernath V |title=Scopolamine (hyoscine) for preventing and treating motion sickness |journal=Cochrane database of systematic reviews (Online) |volume= |issue=3 |pages=CD002851 |year=2007 |pmid=17636710 |doi=10.1002/14651858.CD002851.pub3}}</ref> and is sometimes used in the form of [[transdermal patch]]es (1.5mg) or as a newer tablet form (0.4mg). The selection of a transdermal patch or scopolamine tablet is determined by a doctor after consideration of the patient's age, weight, and length of time treatment is required.

Interestingly, many pharmacological treatments which are effective for nausea and vomiting in some medical conditions may not be effective for motion sickness. For example, [[metoclopramide]] and [[prochlorperazine]], although widely used for nausea, are ineffective for motion-sickness prevention and treatment. This is due to the physiology of the CNS vomiting centre and its inputs from the chemoreceptor trigger zone versus the inner ear. The sedating anti-histamine medications such as [[promethazine]], work quite well for motion sickness, although they can cause significant drowsiness.

[[Ginger]] root is a highly effective [[anti-emetic]] and sucking on crystallized ginger or sipping ginger tea can help to relieve the nausea.<ref>{{cite journal | last = Ernst | first = E. | coauthors = and M. H. Pittler | year = [[2000]] | title = Efficacy of ginger for nausea and vomiting: a systematic review of randomized clinical trials | journal = British Journal of Anaesthesia | volume = 84 | issue = 3 | pages = 367–371 | url = http://bja.oxfordjournals.org/cgi/content/abstract/84/3/367 | format = PDF | accessdate = 2006-09-06 | pmid = 10793599}}</ref> A teaspoon of ground (powdered) ginger root has been proven to be as effective in preventing motion sickness as popular OTC chemicals, but without the drowsiness and sleepiness that is a common side reaction to dimenhydrinate or diphenhydrinate.

[[Soft drink|Soft drinks]] will also help to settle the stomach, and candy or [[Breath mint|breath mints]] will help keep saliva from building up in the mouth.

===Other===

Also, it has been discovered that [[acupressure wristbands]] can be used to prevent motion sickness.

==References==

{{Reflist|2}}

==External links==

{{Wiktionary}}

*[http://www.nlm.nih.gov/medlineplus/motionsickness.html Motion Sickness] from [[MedlinePlus]]

*[http://healthlink.mcw.edu/article/907367055.html Motion Sickness Prevention and Treatment], from a [[Medical College of Wisconsin]] website

*[http://www.motion-sickness.co.uk Visually induced motion sickness research]

* [[Golding JF]]., Motion Sickness Susceptibility Autonomic Neuroscience: Basic and Clinical 129 (2006) 67–76

* [[ארנון רולניק|Rolnick, A.]], & [[Bles, W.]] (1989). Performance and well being under tilting conditions: the effects of visual reference and artificial horizon. Aviation, Space and Environmental Medicine, 60, 779-785

* [[ארנון רולניק|Rolnick, A.]] & [[Gordon, C. R.]] (1991). The effects of motion induced sickness on military performance. In R. Gal & J. Mangelsdorff (Eds.), Handbook of Military Psychology. Chichester: Wiley.

* [[ארנון רולניק|Rolnick, A.]], [[Lubow, R.E.]], 1991. Why is the driver rarely sick? The role of controllability in motion sickness. Ergonomics 34, 867–879.

{{Consequences of external causes}}

[[Category:Neurological disorders]]

[[cs:Kinetóza]]

[[da:Transportsyge]]

[[de:Reisekrankheit]]

[[es:Cinetosis]]

[[fr:Cinétose]]

[[it:Chinetosi]]

[[nl:Reisziekte]]

[[ja:乗り物酔い]]

[[no:Sjøsyke]]

[[pl:Choroba lokomocyjna]]

[[pt:Cinetose]]

[[fi:Matkapahoinvointi]]

[[sv:Rörelsesjuka]]

[[zh:晕动病]]