Overview of jet lag

Jet lag is a temporary sleep disorder that commonly affects travellers who fly across several time zones. It is caused by a mismatch between the body’s circadian rhythm and the destination’s day–night cycle. Symptoms of jet lag include poor nocturnal sleep, daytime sleepiness, fatigue, malaise, cognitive impairment (eg reduced alertness and functioning) and gastrointestinal upset.

Jet lag is worsened by:

• crossing more time zones
• eastward travel
• fatigue caused by inflight conditions (eg hypoxia, dehydration, low bariatric pressure)
• sleep deprivation.

Typically, jet lag spontaneously resolves within a few days; however, it can be a serious impediment to professional performance and general functioning.