What happens if jet lag is not treated?

After crossing time zones, your internal sleep–wake rhythm may still signal sleep or alertness at the wrong local time. You may wake early, struggle to fall asleep, feel sleepy during the day or have a headache. Digestion, appetite and mood can also feel unsettled while your routine is out of step.

Most travel-related symptoms improve as the body clock adjusts, but irregular schedules, bright light at the wrong time, long naps and late caffeine can make the transition harder. Jet lag can also expose or aggravate an existing sleep problem, including insomnia.

Use local time for meals, sleep and activity, and get daylight at a sensible time for the destination. Keep naps short and avoid driving or demanding tasks when very sleepy. Hydration, light activity and a calm evening routine may make adjustment easier.

For repeated travel, pregnancy, chronic illness or severe symptoms, a travel health consultation can help plan timing of light, sleep and medicines. Insomnia management may be useful if sleep difficulty continues after the travel adjustment period.

Seek medical advice if symptoms are severe, continue well after you have returned to a regular local schedule, or prevent safe driving and work. Get urgent help for chest pain, fainting, severe confusion, new neurological symptoms or thoughts of self-harm; these are not symptoms to explain away as jet lag.

How should I time light exposure and sleep for this trip? Is a sleep aid or melatonin appropriate for me? Could another condition be causing the symptoms? When should ongoing difficulty sleeping be assessed as insomnia?