What Causes Jet Lag?

Jet lag is a common sleep disorder suffered by many millions of travelers every day, whether traveling on business or for pleasure. In one recent survey of international business travelers, seventy four percent of those questioned said that they suffered frequently from jet lag.

Jet lag affects people of all ages, although its symptoms vary widely from person to person and tend to be more severe the older you get. Jet lag symptoms also tend to be worse if you are already suffering sleeping difficulties in advance of traveling.

Jet lag also increases with the number of time zones crossed during your journey. If the time difference between your starting point and destination is just two or three hours, then you are likely to experience little or no jet lag. However, once your journey extends across more than three time zones you will begin to experience the symptoms of jet lag, which will tend to worsen as the number of time zones increases.

So what causes jet lag?

Jet lag is caused by a significant and rapid change in time zones which result in a difference between the local time and the time recorded by your body's internal clock.

Let's say that you leave London at 11 o'clock on a Monday morning flying to Bangkok. The flight lasts twelve hours and you arrive in Bangkok at 11 o'clock that same evening London time. However, because you have flown across several time zones the local time in Bangkok is five o'clock on Tuesday morning.

By the time you've cleared immigration and customs and taken a taxi to your hotel, it's probably getting on for seven thirty in the morning and breakfast is being served at the hotel. However, as far as your internal body clock is concerned, it's still only one thirty in the morning and your body wants nothing more than to crawl into bed.

Your body contains its own internal clock which takes its time from the environment responding to such things as temperature, humidity and, most importantly, the normal daily change from daylight to darkness. These environmental factors cause your own body clock to run, much like your mantle clock, on a series of twenty four cycles, often referred to as your body's circadian rhythms.

Much as our lives are controlled by time today, your body clock is also responsible for many of your body's functions. In particular, your body clock tells your body when it is time to shut down for sleep and when it is time to wake up and start the day's activities.

By flying across several time zones and placing your body clock out balance with local time you upset the whole rhythm of your day, giving rise to such things as problems sleeping at night, staying awake during the day and eating when you wouldn't normally eat. This, in turn, leads to jet lag.



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