The prevention and treatment of jet lag

The jet lag syndrome emerged with the rise of long haul air travel. The symptoms include disturbed sleep, increased fatigue, loss of concentration, and increased irritability during the new daytime, and yet difficulties in initiating and maintaining sleep at night. Long flights are also often tiring and uncomfortable (travel fatigue), and the dry cabin air contributes to dehydration. These effects can be distinguished from those of jet lag by comparing flights across time zones, for example from Europe to Asia, with flights of similar length along the same meridian, say to southern Africa, which cause travel fatigue but no jet lag. It is worth trying to minimise travel fatigue in its own rightfor simple practical advice see box.1

Jet lag is due to the desynchronisation between various body rhythms and environmental rhythms. The rhythm most noticeably affected is the cycle of sleep and activity, with the associated changes in physical