Sleeping Disorders

Jet Lag

Jet Lag (also written as jetlag and jet-lag, and also known as Desynchronosis, Dysrhythmia, and Dyschrony) is a condition resulting from alterations to a person's circadian rhythm.  Such alterations may be caused by shift work, transmeridian travel (travel to different time zones in different locations), or altered day length.
The maximum Jet Lag that a person can experience is 12 hours.  If the difference in time between two places is greater than 12 hours, then subtract that number from 24.  For example, there is a 16 hour time difference between Los Angeles (standard time) and Hong Kong.  Thus if you travel between these two places then you will incur 24 − 16 = 8 hours of Jet Lag.
The condition is not linked to the length of flight, but to the transmeridian, that is East-West, distance traveled.  Hence a ten hour flight between Oslo and Johannesburg causes far less Jet Lag than a five hour flight between New York and Los Angeles.
There is no firm agreement as to which direction of travel is worse:  East to West or West to East.  Some people believe that traveling from West to East is worse because you quickly pass through various time zones (a night might only last 3 hours when flying West to East), and because the symptoms of traveling West, such as waking earlier in the morning, can be easier to integrate with ordinary life.

Symptoms

The symptoms of jet lag can be quite varied, though on the whole, an individual may experience the following:
- Dehydration,
- Disorientation and/or grogginess,
- Fatigue,
- Headaches,
- Insomnia and/or highly irregular sleep patterns,
- Irrationality,
- Irritability,
- Loss of appetite,
- Nausea and/or upset stomach, and,
- Sinus irritation,

Causes

Jet Lag is most commonly experienced by people who travel through multiple time zones on a regular basis, as the time relative to the rising and falling of the sun no longer coincides with their body's internal concept of it.  When traveling across a number of time zones, the body clock goes out of sync with the destination time, and so it experiences daylight and darkness contrary to the rhythms it has grown accustomed to.  The body's natural pattern therefore becomes upset as the rhythms which dictate when you should eat and sleep no longer correspond to the environment of your destination.
Jet Lag is also experienced by people who consistently perform shift work, especially when their shift times change on a regular basis.
Jet Lag occurs because the body cannot quickly automatically realign these changed rhythms.  The speed at which your body readjusts itself to new daylight and darkness hours and eating and sleeping patterns is entirely dependent upon the individual.  So while it may take a few days for certain people to readjust to a new time zone, others seem to experience little disruption to their body's natural sleeping pattern.

Diagnosis

Complications / Issues

If you are frequently changing time zone or working long hours or shifts, you do start working at only 60 to 70% of your potential. You lose concentration, you lose judgment, you lose reaction.

Treatment

The state of Jet Lag generally lasts up to a few days or more, depending on the person, and medical experts have deemed that a recovery rate of "one day per time zone" is a reasonable guideline.
Sleep, relaxation, moderate exercise, and sensible diet seem to be the simplest recovery activities.
Good sleep hygiene practices also promote rapid recovery from Jet Lag:
- exercise regularly (but not too close to bedtime),
- ensure that they get enough sleep,
- keep a regular sleep diary, and,
- Reducing stress levels in their lives.
Exposure to sunlight is a factor that helps reset the body's clock.
For people who don't fly multiple times per week, it can be an effective non-drug remedy to skip sleep entirely for one night and one day and then go to bed at a normal destination-area bedtime on the next day.

Prevention

Simple prevention from Jet Lag can be achieved by ensuring that you get a good sleep aboard your flight and drink lots of fluid (but not coffee or alcohol) to reduce the effects of dehydration on the body, caused by the dry air at altitude and the interruption of regular eating/drinking patterns.
Seasoned travelers set their clock to their destination's time zone as soon as practical and join the new rhythm.

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