What is jet lag?

Your sleep and wake signals may arrive at inconvenient local hours. You may feel sleepy during the day, struggle to sleep at night, wake early, or notice reduced concentration. Headache, low energy and changes in appetite can also occur. The symptoms reflect adjustment of the circadian rhythm, rather than a contagious illness.

Use the destination time for meals, sleep and light exposure as soon as practical. Get daylight during the local day, keep evening light softer, drink water and choose gentle activity. A short nap may help, but a long or late nap can make night sleep harder. Avoid driving or safety-sensitive work when very sleepy. A travel-health clinician can help you plan around medicines, sleep conditions and the direction of travel.

Seek advice if sleep disruption or daytime sleepiness is severe, does not begin settling after you return to a regular schedule, or repeatedly affects work and safety. Get urgent help for chest pain, trouble breathing, fainting, sudden weakness, confusion or a severe unusual headache; these are not typical jet-lag symptoms.

Ask whether your medicines or a sleep condition could worsen the adjustment, how to time light exposure for your itinerary, and what to do if you must work or drive soon after arrival.