Jet lag

7 Min Read

What is it

Jet lag can be defined as a dis-orientation in sleep patterns and disturbance of normal body rhythms experienced after flying across several times zones. As anybody who has ever suffered from jet lag knows, it’s no fun. If you travel between the United States and Europe, for example, your body functions for a day or longer according to the clock you left behind, depending upon how many time zones you’ve crossed. This has the effect of putting you out of synch with your new sleeping, waking, and eating schedule.

Westward journeys are less stressful than east-ward: it’s easier for a person’s biological clock to set itself back than forward. Thus, adding a couple of hours to the day may not disrupt sleep patterns, but losing a couple of hours almost always does. Flying north to south has no effect. Jet lag affects not only travelers but shift workers, people in the military, and others who keep odd hours in particular, flight crews who are repeatedly subjected to this kind of stress and yet must turn in high-level performances.


  • Extreme fatigue.
  • Daytime drowsiness.
  • Insomnia.
  • Irritability.
  • Gastrointestinal disturbances.
  • Headaches.
  • Decreased mental alertness, athletic ability, and strength.

What causes it

The phenomenon of jet lag is linked to the fact that human beings operate according to an inborn circadian rhythm (circadian is derived from circa and dies, the Latin words for around the day). This inner body clock regulates practically all physiological functions, including hormone levels. Scientists now believe that the hormone melatonin, which is triggered in the brain by darkness and suppressed by light, influences these daily rhythms. (Taking supplements of melatonin to combat jet lag is not recommended, however.

Researchers believe that jet lag is caused by upsetting the body’s circadian rhythms that regulate sleep. Traveling from one time zone to another, the particular rhythm that the body has for daytime and nighttime is suddenly thrown out of synch by the new daytime and nighttime. The more time zones that have been crossed, the worse the jet lag.

Moreover, the circadian day is actually 25 hours, not 24 and thus it is easier to lengthen our days than to shorten them. This explains why we may feel all right after a plane flight westward across two or three time zones, but can feel exhausted after flying the same distance eastward.

What if you do nothing

Jet lag symptoms will clear by themselves in a matter of hours or days, depending on your age, distance traveled, and how well you prepared for your trip.

Home remedies

Change your sleep time

If it’s possible, try going to bed and getting up an hour earlier for three days before a long eastward trip. For a westward trip, go to bed and get up an hour later. Of course, not everybody can change sleep time so easily. You don’t want to have jet lag before you even depart.

When traveling, try not to do anything that’s likely to cause sleep problems

On the plane, avoid or go easy on alcohol and caffeine, which can disrupt sleep patterns. Drink plenty of flu- ids to prevent the unpleasant effects of dehydration. Heavy meals can interfere with a good night’s sleep, so it’s smart to avoid them. Though the jet lag diet (alternating large high-protein meals with lighter ones for three days before traveling) has had its advocates, there’s little evidence that any diet can forestall jet lag.

Prepare for resting on board

On a night flight, try a sleep mask, wrap-around dark glasses, a neck pillow, a blanket, earplugs, or any device that may help you get a little more shuteye. Stretch out if you’re on an un-crowded flight.

Make quick adjustments

When you reach the new time zone, try to adjust as quickly as possible to new eating and sleeping times, even if it means staying up when you’re tired or eating breakfast when your body says it’s dinnertime.

Try to expose yourself to daylight after a long trip

This doesn’t mean you should get sunburned, of course. But exposure to light may be the means for resetting a lagging or confused biological clock. Indeed, small studies have shown that proper exposure to light can reset circadian rhythms by as much as 12 hours, backward or forward.

According to a recent consensus report in the Journal of Biological Rhythms some studies of light exposure as a cure for jet lag have had encouraging results, but others have not Maybe it will help some people, but so far nobody knows what the optimal times or optimal amounts of light might be. (One report in Nature found that low light, not necessarily sunlight, is probably the synchronizer of our biological clocks.)

Reschedule meetings

Jet lag can wipe out even the best-laid business plans. If you have any business meetings at your new destination, try to schedule them 24 to 48 hours after you arrive there, so you’re be acclimated to your new environment, bright and alert.


Jet lag cannot be entirely prevented, but you can reduce its severity with the measures out-lined.

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