What Is Jet Lag And What Causes It?
What is jet lag?
Jet lag (also often written as jetlag) is a common sleep disorder and, most importantly, it is a symptom, or set of symptoms, and not a disease. When we talk about a jet lag remedy or a jet lag cure therefore we are not talking about overcoming jet lag directly, but are looking at treating the underlying cause or causes.
Jet lag affects millions of long-haul travelers every day, whether traveling for pleasure or on business. In a recent survey of international business travelers, 74% of those questioned said that they suffered frequently from jet lag.
What causes jet lag?
Jet lag (which is also referred to as desynchronosis) is caused by a significant and rapid change in time zones which result in a difference between the local time and time recorded by your body's internal clock.
For example, let's say that you leave London at 9 pm and fly to Singapore. The flight lasts 12 hours and you land in Singapore at 9 am London time. However, because you have flown across several world time zones, the local time in Singapore is 3 pm.
In the space of just 12 hours you have flown half way around the world and your body clock now says that it is 9 am, although the actual time in Singapore is 3 pm.
So you can see the problem. Later in the day when everybody else is going to bed, your body clock will still be showing the time as late afternoon and you won't be ready for bed yet. Similarly, the following morning when the bus arrives at your hotel at 10 am to take you on a sightseeing tour, your body clock will still be registering 4 am and you will be looking for a few more hours of sleep before you get up and going.
Your body contains it's own internal clock which is powered by the environment around you including such things as temperature, humidity and, in particular, the normal daily change between daylight and darkness. These environmental factors cause your internal clock to run, rather like a normal clock, on a series of 24 hour cycles, sometimes referred to as your body's circadian rhythms.
Your body clock in turn triggers certain events within your body, the most obvious of which is telling your body when to shut down for sleep and when to wake up and get going.
The fact that your body clock is out of step with local time upsets the whole rhythm of your day, giving rise to problems sleeping at night, staying awake during the day and eating when you wouldn't normally eat, amongst other things. This, in turn, leads to jet lag.