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Jet lag, also jetlag or jet-lag, is a physiological condition which is a consequence of alterations to the circadian rhythm. Such disturbances result from shift work, daylight saving time, altered day length, or as the name implies, transmeridian travel as on a jet plane. They are known as desynchronosis, dysrhythmia, dyschrony, jet lag, or jet syndrome. The condition is generally believed to be the result of disruption of the "light/dark" cycle that entrains the body's circadian rhythm. It can be exacerbated by environmental factors. Image File history File links Emblem-important. ... Décalage Horaire (Known as Jet Lag in English language regions) is a 2002 film starring Juliette Binoche and Jean Reno. ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... This article or section does not cite any references or sources. ... A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. ... Second shift redirects here. ... Although DST is common in Europe and North America, most of the worlds people do not use it. ... Jet aircraft are aircraft with jet engines. ... A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. ...

The condition of jet lag may last many days, and medical experts have deemed that a recovery rate of "one day per time zone" is a fair guideline.^{[citation needed]} Good sleep hygiene promotes rapid recovery from jet lag: in fact sleep, relaxation, moderate exercise, and sensible diet seem to be the simplest recovery methods. A medical guideline (also called a clinical guideline and clinical protocol) is a document with the aim of guiding decisions and criteria in specific areas of healthcare, as defined by an authoritative examination of current evidence (evidence-based medicine). ... Sleep hygiene is the practice of following simple guidelines in an attempt to ensure more restful, effective sleep which can promote daytime alertness and help treat or avoid certain kinds of sleep disorders. ...

However, since the experience of jet lag varies among individuals, it is difficult to assess the efficacy of any single remedy. Age may also be a factor on the severity of jet lag, as younger people will suffer worse jet lag than older people would^[1].

Women are more susceptible to jet lag than are men^[2] this is in part because estrogen is often vulnerable to jet lag-like conditions^[3]. Estriol. ...

Most chemical and herbal remedies, including the hormone melatonin, have not been tested nor approved by official agencies such as the U.S. Food and Drug Administration. Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ... “FDA” redirects here. ...

A recent study in hamsters showed that sildenafil (also known as Viagra) aided in a 50% faster recovery from shifts comparable to eastward travel experienced by humans and was effective starting at low doses.^[4] However, this use has not been tested in humans and is considered an off-label use by the drug's manufacturers. Sildenafil citrate, sold under the names Viagra, Revatio and generically under various other names, is a drug used to treat male erectile dysfunction (impotence) and pulmonary arterial hypertension (PAH), developed by the pharmaceutical company Pfizer. ... Sildenafil citrate, sold under the names Viagra, Revatio and generically under various other names, is a drug used to treat male erectile dysfunction (impotence) and pulmonary arterial hypertension (PAH), developed by the pharmaceutical company Pfizer. ...

Cause

When traveling across a number of time zones, the body clock will be out of sync with the destination time, as it experiences daylight and darkness contrary to the rhythms to which it has grown accustomed. It is not common to get jet lag from a crossing of only one or two time zones. In jet lag, the body's natural pattern is upset, as the rhythms that dictate times for eating, sleeping, hormone levels and the body temperature rhythm no longer correspond to the environment nor to each other in some cases. Jet lag occurs because the body cannot immediately realign these rhythms. The speed at which the body readjusts itself to new daylight/darkness hours is individually determined. Thus, while it may take several days for some people to readjust to a new time zone, others seem to experience little disruption to their body's natural patterns.

There have been links made with jet lag and contamination of cabin air by TCP or Tricresylphosphate from contaminated engine bleed air, which supplies the cabin pressurisation system, although these have not been substantiated, and aircraft manufacturers are adament that air quality is generally high.^{[5] [6] [7]} Timezone and TimeZone redirect here. ... A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. ... TCP is an abbreviation of all of: Transmission Control Protocol Thermal conversion process Top Cow Productions Tool Center Point of a robot A number of chemical substances: Trichlorophenol, a fungicide Trichlorophenylmethyliodosalicyl, a germicide, see TCP (antiseptic) Tricresylphosphate, a lubricant, gasoline additive, plasticizer, and flame retardant Thienylcyclohexylpiperidine, which has been sold... Bleed air in jet turbines is compressed air taken from within the engine, after the compressor stage(s) and before the fuel is injected in the burners. ...

Symptoms

The symptoms of jet lag can be quite varied, though on the whole, an individual may experience the following^[8]:

• Dehydration (possibly because of dry air in the plane)
• Loss of appetite
• Nausea and/or upset stomach
• Headaches and/or sinus irritation
• Fatigue
• Disorientation and/or grogginess
• Insomnia and/or highly irregular sleep patterns
• Irritability, irrationality
• Mild depression

Frequent changes of time zone or working long hours or shifts may reduce work output to only 60 to 70% of one's potential.^{[citation needed]} Dehydration (hypohydration) is the removal of water (hydro in ancient Greek) from an object. ... The appetite is the desire to eat food, felt as hunger. ... This article does not cite any references or sources. ... The tone or style of this article or section may not be appropriate for Wikipedia. ... Exhaustion redirects here. ... Orientation is a function of the mind involving awareness of three dimensions: (1) time, (2) place and (3) person. ... This article is about the sleeping disorder. ... In everyday language depression refers to any downturn in mood, which may be relatively transitory and perhaps due to something trivial. ...

The condition is not linked to the length of flight, but to the transmeridian (i.e., east-west) distance traveled. Hence, a ten-hour flight between Frankfurt and Johannesburg (going south, staying roughly on the same meridian) is much less inducive of jet lag than a five-hour flight between New York and Los Angeles or vice versa. Also, the International Date Line should not be confused as contributing to jet lag, as the maximum possible disruption is plus or minus 12 hours. If the time difference between two locations is greater than 12 hours, subtract that number from 24. (For example, a 20 hour time difference equals 4 hours of jet lag). Layovers can complicate this simple arithmetic, however.   (German: , English: American English: ) is the largest city in the German state of Hesse and the fifth-largest city in Germany, with a mid-2007 population of 663,567. ... This article is about the city in South Africa. ... This article is about the state. ... Flag Seal Nickname: City of Angels Location Location within Los Angeles County in the state of California Coordinates , Government State County California Los Angeles County Mayor Antonio Villaraigosa (D) Geographical characteristics Area     City 1,290. ... “Date line” redirects here. ... In transportation, a layover or lay over is some form of a break between trips of parts of a single trip [1]. Depending on the mode of transportation, its meaning may vary. ...

Jet lag can be especially difficult near the north and south poles, where there are extreme periods of daylight or darkness, depending on the time of year, which often causes insomnia or hypersomnia. For other uses, see North Pole (disambiguation). ... For other uses, see South Pole (disambiguation). ... This article is about the sleeping disorder. ... Hypersomnia, also known as excessive daytime sleepiness (EDS), is excessive amount of sleepiness. ...

Direction of Travel

There seems to be some evidence that traveling west to east is the more disruptive. This may be because flights to the east run counter to the circadian rhythm.^[9] Most people have a circadian period which is a bit longer than 24 hours, making it easier to stay up later than to get up earlier. A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. ...

It may also be that flights to the east are more likely to require people to stay awake more than one full night in order to adjust to the local time zone. For example, comparing a typical schedule for a traveler flying to the East vs a traveler flying to the West:

• Westward from London to Los Angeles, VIA BA0279, Jan 29, 2008. Time zone difference 8 hours.

Westward	Biological clock	Los Angeles local time
Departure	JAN 29 - 10:05	JAN 29 - 02:05
Arrival	JAN 29 - 21:10	JAN 29 - 13:10
Bedtime	JAN 30 - 06:00	JAN 29 - 22:00

• Eastward from Los Angeles to London, VIA BA0278, Jan 29, 2008.

Eastward	Biological clock	London local time
Departure	JAN 29 - 15:59	JAN 29 - 23:59
Arrival	JAN 30 - 02:05	JAN 30 - 10:05
Bedtime	JAN 30 - 14:00	JAN 30 - 22:00

The first scenario is equivalent to staying up all night and going to bed at 6am the next day — 8 hours later than usual. But the second scenario (eastward) is equivalent to staying up all night and going to bed at 2pm the next day — 16 hours after the time one would otherwise have gone to bed.

Net Lag

People depending of updated information from other time zones, may suffer from biological clock variations causing them to be less time adjusted to the social routines of the surrounding geographical region and may suffer from similar symptoms of jet lag during the adaptation period.

See also

• Chronobiology
• Light therapy
• China Airlines Flight 006#The aftermath

Chronobiology is a field of science that examines periodic (cyclic) phenomena in living organisms. ... Bright light therapy is a common treatment for seasonal affective disorder. ... China Airlines Flight 006 was a daily non-stop flight departing from Taipei at 4:40 pm and arriving in Los Angeles at 1:25pm local time. ...

References

1. ^ http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP010468
2. ^ http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP010468
3. ^ http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADP010468
4. ^ "Viagra could aid jetlag recovery", 2007-05-22. Retrieved on 2007-05-22. (publisher = BBC News) 
5. ^ [http://www.king5.com/health/stories/NW_022508HEB_cabin_air_SW.2a169305.html Do you know what you're breathing at 30,000 feet?, Date = unknown, Author = King5.com, Access date = 2008-3-12
6. ^ [http://www.toxicfreeairlines.com The Toxic Free Airlines website, Date = unknown, Author = unknown, Access date = 2008-3-12
7. ^ [http://www.aerotoxic.org The Toxic Free Airlines website, Date = unknown, Author = unknown, Access date = 2008-3-12
8. ^ "http://www.medicinenet.com/jet_lag/article.htm".
9. ^ "http://www.gi.alaska.edu/ScienceForum/ASF12/1261.html".