What should you know about jet lag for days?

Your brain uses light, darkness, meals, and activity to time sleep and alertness. A long flight across time zones can make those signals disagree. Common effects include waking during the local night, sleepiness at an unsuitable time, reduced focus, mood changes, appetite disruption, and headache. The direction and distance of travel, travel fatigue, and your sleep before the flight can all shape the experience.

Follow the local clock soon after arrival: eat and move at local daytime, then keep the evening calm and darker. Spend time outdoors when it is light, but protect your planned bedtime from bright light. Keep naps short enough that they do not replace nighttime sleep. Drink water, limit alcohol, and use caffeine earlier rather than near bedtime. Gentle activity may improve alertness. If you are sleepy, postpone driving, swimming alone, or tasks involving machinery.

Speak with a clinician if symptoms are intense, continue without improvement, or prevent normal work and care of others. Seek urgent help for severe breathing difficulty, fainting, sudden confusion, chest pain, or a sudden severe headache. Ask for advice if a baby, older adult, or person with a long-term condition is having marked sleep disruption after travel.

When should I seek morning or evening light? Is a nap appropriate for my schedule? Could my medicines or health conditions affect adjustment? What precautions should I take if I must work or drive?