Clinical Definition

Jet lag, also called time zone change syndrome, is a sleep disorder affecting travelers who cross several time zones. It can occur when the body’s biological clock becomes out of sync with the local time, and as a result those affected may be afflicted with insomnia, daytime sleepiness, moodiness, reduced performance and other cognitive problems.

In Our Own Words

While not a serious condition, jet lag can make it difficult to enjoy time off at your destination, as well as resuming your normal routine upon your return. Because this sleep disorder occurs when your body’s internal rhythms do not correspond to the local time at your destination, one way to reduce jet lag risk (before departing) is to shift your body’s clock to the destination time a few days before. If you are traveling west, for instance, go to bed an hour or two later than usual; reverse the strategy if you are traveling east.