What is Jet Lag?

Travel across time zones can result in jet lag, casing either sleeplessness or fatigue.

Jet lag is a short-term bodily condition that leads to sleeplessness and tiredness among other symptoms due to air travel across different time zones. The disorder results from the change in the day-to-day regularity due to the long distance travel. For example, if a person travels from London to New York, he/she would feel as if the time were five hours later than the local time.

A person can experience jet lag for many days before he or she adjusts entirely to the new time zone. Many airline pilots, frequent travelers, and flight crews are the victims of jet lag, and airlines’ regulations on jet lag are there to help in combating the pilot fatigue that results from jet lag. In addition, a suggested guideline for recovery from this condition states that a period of 24 hours is enough for recovery for every time zone that the traveler crosses. Thus, if a person passes three time zones, then a recovery period of three days would be necessary before the traveler is adjusted to the time.


The primary cause of jet lag is the incapability of a person's body to adjust to the time in another zone as soon as he or she lands there. The body clock would typically be out of synchronization when a person travels across several time zones. Mainly, the body would experience daylight and darkness that it has not been used to, making its natural pattern upset. The reason behind the upset is that the rhythms that usually dictate time for sleep, meals, variations in body temperature, regulation of hormones, and other body functions would lose correspondence with the surrounding. Hence, the body reaches a point at which it cannot cope with the immediate environment.

The body of an individual and the direction of travel determine the speed at which that body would adjust to the new schedule. Some individuals would experience little disruption from the change in time zones while others would need several days to recover from jet lag. It is important to note that crossing the International Date Line is not a contributing factor to jet lag by itself since the measurement of jet lag is based on the number of time zones that a traveler crosses. The maximum time possible is plus or minus twelve hours, and in cases whereby the difference of time between any two zones is larger than twelve hours, the difference must be subtracted from 24.


The best way to manage jet lag is the cautious, controlled exposure and avoidance to bright light to the eyes. Light stimulates the readjustment of a person to the sleep-wake program. It is an essential requirement that eliminates the hormone melatonin, which is produced in darkness and dim light. Thus, timed exposure to light is the most effective method of matching the travelers' circadian rhythm with the anticipated progression in their last stop. Another way of managing jet lag is short-acting sleep medication, which improves the quality of sleep. Moreover, scheduling meals and exercise can be practical approaches for managing jet lag.


More in Did You Know