Why can jet lag feel worse when travelling east?

Your circadian rhythm is set by light, sleep, meals and daily activity. Eastward travel moves the local schedule earlier, so evening may arrive before you feel ready for sleep, while morning may come before your body has completed its usual rest. This mismatch can cause difficulty sleeping, early waking, tiredness, reduced concentration or a headache. Travel across time zones can also involve dehydration, long periods of sitting and disrupted routines, which may add to how you feel.

Jet lag is different from a persistent sleep disorder, although repeated poor sleep can resemble insomnia. Symptoms generally ease as the body clock aligns with local time.

Before departure, gradually move bedtime and waking time earlier when practical. On arrival, use local time for meals and sleep, seek morning daylight, keep activity gentle, and avoid long naps that make bedtime harder. Keep the bedroom dark and quiet, drink water, and limit alcohol. Caffeine late in the day can delay sleep. A travel-health consultation can help you plan light exposure or discuss medicines, especially if you take regular treatment or have another sleep condition.

Arrange medical advice if sleep disruption continues after your body has had time to adjust, repeatedly affects work or driving, or comes with severe daytime sleepiness, confusion, fainting, chest pain or breathing difficulty. Seek urgent help for thoughts of self-harm or an inability to stay awake safely. A clinician can check whether another illness, medication or sleep problem is contributing.

Ask whether your symptoms fit jet lag, how to time light and sleep, and whether any sleep aid is suitable with your health conditions and medicines. You can also ask when it is safe to drive or return to demanding work.