Managing a 12-hour jet lag time difference

Your internal clock may initially signal sleep near the destination's daytime and alertness near bedtime. Adjustment is gradual, so planning around safety matters more than forcing immediate sleep.

Jet lag can present with difficulty falling asleep, early waking, daytime drowsiness, headache, irritability, poor focus and changes in appetite or bowel habits. Travel fatigue from a long flight can occur at the same time.

Direction of travel, departure sleep, light exposure, meal timing and individual sleep patterns all influence the experience. A single rough night at the destination does not by itself establish insomnia.

Use the destination's local schedule for meals, activity and sleep as soon as practical. Daylight at appropriate local times helps reset the clock; dimmer light and a calm routine before local bedtime support sleep.

Keep naps brief enough that they do not replace the main sleep period. Stay hydrated, limit alcohol, and avoid using extra caffeine late in the local day. Do not drive, operate machinery or make safety-critical decisions when drowsy.

Arrange medical advice if sleep disruption remains troublesome after your schedule has had time to settle, repeatedly affects work or mood, or occurs without recent time-zone travel. A clinician can check for another sleep or health problem.

Seek urgent help for chest pain, severe breathing difficulty, fainting, new confusion, one-sided weakness or a sudden severe headache. These are not routine jet lag features and should not be managed simply by sleeping them off.

Before travel, ask how to time regular medicines across the new time zone and whether a sleep aid is suitable for your health and itinerary. Share your flight schedule, medical conditions, pregnancy status and any medicines that cause sedation.