Jet lag

Jet lag is a temporary sleep-cycle disturbance that happens when you cross several time zones quickly. Your body's internal clock is set to your home time zone and takes days to adjust to the new one. Jet lag is not a disease — it's a normal response to rapid travel across time zones and usually gets better within a few days.

Symptoms

• Trouble falling asleep or waking at odd hours
• Tiredness during the day
• Poor concentration, slow thinking
• Irritability
• Digestive upset — constipation or diarrhoea, reduced appetite
• Headache, dehydration

Symptoms are usually worse travelling eastward (losing hours) than westward. Crossing fewer than 3 time zones usually doesn't cause significant jet lag.

Reducing jet lag

• Start shifting your sleep schedule 1-2 days before travel — earlier if going east, later if going west
• Get sunlight when you arrive — daylight is the strongest signal for the body clock
• Stay hydrated; limit alcohol and caffeine on the flight
• Try to sleep at your destination's night time, even on the flight
• Eat meals aligned to destination time
• Short naps can help but limit to 20-30 minutes
• Melatonin supplements, used short-term under medical advice, may help for eastward travel across many time zones

Jet lag usually resolves in a few days. See a doctor if sleep problems persist after you've returned to your usual routine.