Crossing more than 3 time zones may cause jet lag or disrupt your body’s internal clock. Try preventing jet lag by anticipating the change and stretching when you can, among other strategies.
Traveling across time zones, especially multiple at a time, may cause jet lag. It’s a temporary sleep condition that affects your energy and alertness.
Also called desynchronosis or circadian dysrhythmia, jet lag can interfere with your day and affect your well-being. Preparing for jet lag, and possibly preventing it, may help you ensure it doesn’t disrupt your next trip.
Symptoms of jet lag usually appear immediately or within 12 hours of arriving at your new location and may last several days.
For travelers who cross 3 or fewer time zones, symptoms may be more likely due to fatigue than jet lag. Your jet lag experience may also depend on your direction of travel.
The symptoms you experience can vary from person to person and after each trip. If you have jet lag, you’ll typically experience at least one of the following symptoms after crossing 3 time zones, according to the CDC:
- gastrointestinal disturbances
- decreased appetite and interest in eating
- headache
- inability to concentrate
- changes in mood, including anxiety, depression, fatigue, irritability
- difficulty performing mental and physical tasks
- decreased sleep quality
When to seek help
Symptoms of jet lag are typically mild for many people. If you experience severe symptoms, like cold sweats, vomiting, or fever, you may be experiencing something else, such as:
- a virus
- a cold
- altitude sickness
If these symptoms last more than 24 hours, contact a doctor for treatment.
Your body is naturally set to a 24-hour cycle, known as your circadian rhythm. This internal clock
- body temperature
- hormone fluctuations
- other biological functions
If you’re traveling a distance that takes you across more than 3 time zones, you’re at a higher risk of jet lag. Jet lag disrupts your internal clock and, therefore, body processes. Here’s how:
Your clocks don’t align
When you travel, your internal clock may no longer align with the time in your new location.
For example, if you travel from Atlanta at 6 p.m. local time and arrive in London at 7 a.m. local time, your body will think it’s 2 a.m. In this case, you’ve traveled across 5 time zones, and your body is still stuck in the Eastern time zone.
To overcome this jet lag and reset your internal clock, you’d need to stay awake for another 12 to 14 hours.
Sleep timing
Sleeping while traveling, if you’re not driving and especially while flying, can help you adjust to the new time zone. You may, however, find it difficult to sleep while traveling.
On the other hand, you might sleep too much and throw off your internal clock that way.
Sunlight
Too much sunlight in a plane’s cabin or getting too much screen time can also affect your internal clock. This is because light
The hormone melatonin helps your body prepare for sleep. Your brain releases it at night when the light is low. During the day or when it’s bright, your body slows melatonin production, which helps you be more awake.
Travel fatigue
A 2019 research review shows that travel fatigue contributes to jet lag.
Changes in cabin pressure and high altitudes during air travel may contribute to some symptoms of jet lag, regardless of travel across time zones.
This can happen because the barometric pressure on planes tends to be lower than air on the ground.
This is similar to being on an 8,000-foot (2.44 km) mountain. While there’s just as much oxygen in the air, the lower pressure may result in less oxygen reaching your bloodstream (hypoxemia). Lower oxygen levels may make you lethargic.
Some people may get altitude sickness when traveling on a plane. This can cause symptoms that may worsen jet lag like:
Dehydration
If you don’t drink enough water during your flight, you can get slightly dehydrated. Low humidity levels in planes may cause more water loss.
Coffee and alcohol
Drinking coffee, tea, and other caffeinated beverages may prevent you from getting enough sleep while traveling. Caffeine can also cause dehydration.
Drinking alcohol might make you drowsy, but it can worsen the quality of sleep. Alcohol may also cause fatigue, headache pain, nausea, and other side effects that worsen jet lag.
Other factors
The more time zones you cross, the more severe your symptoms of jet lag may be.
Travelers over 60 years old may find it more difficult to cope with jet lag than younger travelers. Young travelers, including children, may have fewer symptoms and adjust to the new time more quickly.
The direction you’re flying can have a big effect on your jet lag symptoms, too.
Symptoms tend to be more severe when traveling eastward. Staying awake later to help your body adjust to a new time zone is easier than forcing your body to go to sleep earlier.
You can help prevent or reduce jet lag by following these tips and strategies:
Sleep while traveling
Try to sleep if you’re traveling eastward and into a new day. Bring earplugs and sleep masks to help reduce noise and light.
Stay awake for a few hours before you land
If you’re arriving at your new destination while it’s nighttime there, this is when it’s a good idea to use light to rewire your sleep schedule.
Go to bed when you arrive and wake up in the morning to adjust to the new time zone.
Select flight times strategically
Pick a flight that arrives in the early evening. This way, staying up until it’s time for bed in your new time zone isn’t as hard.
Power nap
If bedtime is too far out and you need a nap, take a nap of no more than 20 to 30 minutes. Sleeping longer than that may prevent sleep later in the night.
Plan extra days
Arrive at your destination a few days early if you can to adjust to the time zone. This is especially helpful for athletes or if you have an event or meeting to attend.
Anticipate the change
If you’re traveling eastward, try getting up several hours earlier for a few days before your departure.
If you’re traveling westward, do the opposite. Stay awake later and wake up later to help you adjust before you even leave for your final destination.
Stay away from alcohol and caffeine
Avoid alcohol and caffeine the day before and the day of your trip. They may ultimately make the symptoms of jet lag worse.
A 2024 mouse study found that sweetened caffeine
Jet lag diet
Avoid salty and sugary foods while traveling. Stay hydrated with more fresh fruit and vegetables and try to avoid overeating.
A balanced diet may help reduce some jet lag symptoms like:
- low quality sleep
- fatigue
- bloating
- upset stomach
Get some exercise
It can be difficult to avoid sitting while on a long trip, but a little exercise may help you sleep better. Try to stretch your legs whenever you can, but stand up only when it’s safe.
If you have a layover, walk around the airport or stand instead of sitting at your departure gate. If you’re driving, stop at rest areas frequently to get some exercise.
Drink herbal tea
Choose non-caffeinated herbal teas instead of coffee or caffeinated teas. A 2019 research review found that chamomile tea shows that drinking chamomile tea may
Jet lag doesn’t always require treatment, but if the symptoms are bothersome and prevent you from performing your daily tasks, a few options are available.
Sunshine
The sun tells your body it’s time to be awake. If you’ve traveled westward, research suggests maximizing exposure to sunlight may help overcome jet lag.
The same strategy, however, may be counterproductive for eastward travel.
Light therapy
Lightboxes, lamps, and visors can help reset your internal clocks. The artificial light simulates the sun and cues your body to be awake.
Once you arrive at your new destination, you may use this treatment to help you stay awake during periods of drowsiness so your body can better adjust.
Melatonin
You can take over-the-counter (OTC) melatonin supplements to trigger sleep when your body is fighting it. Melatonin is fast-acting, so take it no more than 30 minutes before you can sleep.
Make sure you sleep a full 8 hours when you take it. Melatonin may make you drowsy if you wake up before the effects have worn off.
Sleeping tablets
If you experience insomnia when you travel, or if you have difficulty sleeping in new places, talk with your doctor about sleeping pills.
Some of these medications are available as OTC products, but your doctor can prescribe stronger versions if necessary.
Sleep medication has several side effects, so be sure to talk with your doctor and understand what they are before you take anything.
Meal timing
Your major organs have their own circadian rhythms. Altering when you eat can help your body adjust to jet lag. Your body may signal hunger at times close to when you would typically eat. If you can, ignore those hunger cues.
Eat at the appropriate time in your new time zone to help your body follow the new cues. The foods you eat may also
Hot baths
Take a relaxing hot bath or shower before you go to bed. According to a 2019 research review, a warm shower or bath
Other home remedies
Some other tips to follow before you travel are:
- Rest well beforehand, and don’t start your journey sleep-deprived.
- Have a light dinner a few hours before going to bed.
- Avoid computer, TV, and phone screens for a few hours before you sleep and silence their notifications.
- Dim the lights a few hours before bedtime.
- Get a full night of sleep on the first night at your new location.
- Use a white noise machine to drown out other noises.
- Adjust your schedule accordingly.
It may take several days for your body to adjust to a new time zone. Aligning your eating, working, and sleeping schedules immediately with your new location can help speed up the process.
While you adjust, you may experience symptoms of jet lag. Jet lag will likely end in a few days after you arrive.
Connect with us!
Sign up for our Sleep Well newsletter and explore our information hub!