Why does jet lag cause headache?

Your internal clock uses light exposure, sleep and regular routines to time alertness and rest. Crossing time zones can temporarily put that clock out of step with the local day. Poor or fragmented sleep can lower your tolerance for usual triggers, while dry cabin air, less fluid, alcohol, caffeine changes and skipped meals may add to a headache. Headache is a common presentation of Jet Lag, but a headache after travel can also have another cause.

Drink water regularly, eat simple meals at local meal times and spend time in daylight once you arrive. Aim for a consistent local bedtime and avoid driving or making safety-critical decisions if you are very sleepy. Gentle movement may help you settle into the new schedule. If you use pain relief, choose an option that is normally safe for you and follow the label or a pharmacist's advice.

Seek urgent medical assessment for a sudden severe headache, a headache after a head injury, or headache with fainting, confusion, weakness, trouble speaking, a stiff neck, fever, repeated vomiting or new changes in vision. Arrange a clinical review if the headache persists, keeps returning, or differs clearly from your usual headaches.

Mention the countries crossed, the timing of symptoms, your sleep, fluid intake, medicines and any associated symptoms. You can ask whether migraine, infection, high blood pressure or a medicine effect should be considered, and which pain relief is suitable alongside your health conditions.