Overview
Jet lag is a short-term sleep and circadian rhythm problem that can happen after flying quickly across multiple time zones. Your internal body clock stays closer to your original time zone for a while, even though local time has changed. This mismatch can affect sleep, energy, thinking, and digestion.
Key Symptoms
Symptoms vary from person to person but often include difficulty falling asleep at the new local bedtime, waking too early, or feeling sleepy at the wrong time of day. Many people also notice fatigue, reduced concentration, irritability, headache, and stomach upset. Symptoms are usually more noticeable after crossing several time zones.
Causes and Risk Factors
Jet lag is caused by rapid travel across time zones, which disrupts the body's circadian rhythm. The more time zones crossed, the greater the mismatch may be. Eastward travel may be harder because it often requires falling asleep earlier than your body expects. Stress, dehydration, alcohol, poor sleep before travel, and irregular schedules can make symptoms feel worse.
Who Is Affected
Anyone who travels quickly across time zones can develop jet lag. It can affect tourists, business travelers, airline crew, athletes, and people visiting family abroad. Older adults, people with sleep problems, and travelers on very short trips may find adjustment more difficult.
Prevention
Before travel, some people find it helpful to gradually shift sleep and wake times toward the destination schedule. During and after travel, getting light exposure at appropriate local times can help the body clock reset. Staying hydrated, avoiding heavy alcohol use, planning rest, and trying to sleep according to local time may also reduce symptoms. If you have an eye condition, bipolar disorder, or another health condition affected by sleep or light, ask a healthcare professional before using strong light-based strategies.
Diagnosis and Tests
Jet lag is usually recognized from the travel history and the timing of symptoms after crossing time zones. Tests are not usually needed for short-term symptoms that improve over time. If sleep problems continue, or if symptoms began without travel, a healthcare professional may look for other causes such as insomnia, illness, medication effects, or another sleep disorder.
Treatment Categories
Management focuses on helping the body adjust to the new time zone and easing symptoms. Common approaches include timed light exposure, keeping a local sleep schedule, planned naps kept short if needed, and limiting things that disturb sleep such as late caffeine or alcohol. Some people ask a healthcare professional about medicines or melatonin products, but these are not appropriate for everyone and can interact with health conditions or other medicines.
Living With It
Jet lag is usually temporary, but it can affect work, school, driving, and enjoyment of travel. Try to allow extra time for rest, important decisions, and activities requiring full attention, especially in the first days after arrival. If you travel often, keeping a consistent routine when possible and planning recovery time may help.
Diet and Lifestyle
Simple habits can support adjustment. Drink enough water, eat meals at local times, and get regular movement such as walking after arrival. Avoid relying on alcohol to sleep, and be cautious with caffeine because it can worsen sleep if used late in the day.
When to Seek Medical Care
Seek medical advice if symptoms are severe, last longer than expected, or keep happening with travel in a way that disrupts daily life. Also seek care if you have major mood changes, ongoing insomnia, fainting, chest pain, shortness of breath, or symptoms that do not fit the usual pattern of jet lag. A healthcare professional can check for other sleep, mental health, heart, lung, or digestive problems.