Jet Lag: Symptoms, Risk Factors, and More

If you’ve ever travelled across the country, or even halfway across the country, you’ve likely felt the effects of jet lag. Jet lag is that general lethargy and crankiness we feel after bouts of air travel.

While jet lag is extremely common, it’s also fairly simple to prevent, given you take the right precautions. Keep reading to learn how to recognize when you have jet lag, how to avoid it, and how to recover if you do end up feeling it.

What is jet lag?


Jet lag occurs with rapid travel across time zones, resulting in a misalignment between the timing of body’s circadian rhythms with those of the external physical environment.

Technically, jet lag is a temporary sleep disorder. It is classified as a secondary circadian dysrhythmia and as a circadian rhythm sleep disorder.

Circadian rhythm is another way of describing your body’s internal clock. Your brain uses cues from your external environment to inform your sleep-wake cycle. For example, your brain relies on the level of sunlight to recognize when it’s time to wake up and when it’s time to go to bed. This is why people in extreme north or south climates are at increased risk for seasonal depression and associated sleep problems, such as hypersomnia (excessive sleep) during the winter when there’s less light outside. It’s also why using your electronics at night can wake you up.

Your brain relies on these light cues to determine when it should begin melatonin production, the hormone responsible for inducing and regulating your sleep. Your melatonin levels rise at night, reaching their peak while you sleep, and are lowest during the day.

Melatonin levels vs body temperature and sleep cycle

When you travel far distances, whether laterally or longitudinally, you find yourself in an environment with different circadian cues than your brain is used to. Travel east or far north, and it gets darker sooner.  Conversely, it gets darker later if you travel west or further south.

What is social jet lag?

Social jet lag is the disconnect between biological time and social time.  It’s easily seen in night owls expected to get to the office early. People with advanced sleep phase disorder or delayed sleep phase syndrome (DSPS) have sleep-wake cycles that are offset – or delayed – from normal. As a result, they feel out of sorts when restricted by social convention to be alert at the “wrong” time for them and consequently have symptoms like those of jet lag. Daylight Savings Time makes social jet lag worse for a lot of people, night owl or not.

Social jet lag is different than typical jet lag, and can be experienced without traveling, as in the case of night owls or people with DSPS. However, it can also present in instances of regular jet lag. A good example is going out to dinner when it’s local time at your destination, even though you’d much rather be in bed.

Jet lag symptoms

About a third of people experience jet lag to a minimal extent, while another third experience more extreme symptoms. Common symptoms of jet lag include:

  • General malaise
  • Daytime sleepiness
  • Difficulties initiating or maintaining sleep (i.e. insomnia)
  • Early waking
  • Impaired performance
  • Reduced alertness and difficulty focusing
  • Increased irritability
  • Digestive and bowel movement problems

Symptoms are worse the farther you travel, but traveling east is always worse than traveling west. Eastward travel generally results in difficulty falling asleep and westward travel in difficulty maintaining sleep.

Jet lag can also be made worse by the airplane itself. Airplanes tend to have poorer air quality, lower humidity, and cramped conditions. Lower humidity results in dehydration, while being forced to sit still for a long flight makes the body achy.

Who’s at risk for jet lag?

Morning larks are more affected than night owls, as are people over age 50. People who travel frequently, such as flight crews and business travelers, are most at risk for jet lag, since they are constantly in different time zones and therefore their body has trouble settling into a steady circadian rhythm.

People with pre-existing sleep issues or stress also tend experience stronger symptoms, as well as anyone who overindulges in caffeine or alcohol.

How long does jet lag last?

These symptoms usually last for several days until the traveler adapts to the new time zone. A good rule of thumb is that it takes about a day per time zone travelled to recover.

Senior citizens generally need longer to recover from jet lag. Their circadian cycles are slower to adjust to the new time zone.

Eastward travel (requiring advancing circadian rhythms and sleep-wake hours) is usually more difficult to adjust than westward travel.

If you travel somewhere with a higher altitude, expect that to lengthen your recovery time, too. It can take as long as 3 weeks for your body to fully adjust, thanks to the lower oxygen levels at altitudes of 13,200 feet or more.

How to avoid jet lag

While getting rid of jet lag will take some time, there are plenty of steps you can take to minimize its troublesome symptoms. Below we’ve organized our top tips for travelers before, during, and after your flight.

Before you fly

  • Book a flight that suits your sleep schedule. For long trips, get a red-eye so you can sleep through the night and practically avoid any disruption to your sleep schedule. If you have trouble sleeping while you fly, try to arrive an hour or two before bedtime so you can fall asleep as soon as you reach your destination.
  • Choose a window seat so you can lean against the window and not be disrupted by your row-mates needing to get up and use the restroom. If you can afford it, purchase one with more legroom or even a first-class seat so you can sleep in luxury.
  • If your trip is high-stakes, whether for a personal reason like meeting a partner’s parents or work-related like an interview, try to arrive a day or two early to allow yourself to fully adjust and recover from jet lag so you can be at your best.
  • Gradually adjust your schedule before your trip. In the days leading up to your flight, adjust your bed- and meal-times by 1 hour each night according to the amount of time zones you’ll be traveling. Schedule earlier for eastward travel and later for westward travel.

The day of your flight

  • Make sure that everything in your life is in order – in other words, make sure you don’t spend the travel time worrying about anything. Pack the night before your trip if possible.
  • Try not to fly tired, hungover, or sick. Go to bed a bit earlier the night before just to make sure you’re as well-rested as possible.
  • Dress comfortably for the flight, and bring soft slippers with you so you can take off your shoes. Also bring blindfolds, neck rests, or earplugs – anything to help you sleep.
  • Download soothing music, guided meditation, or white noise apps to calm your mind – and help you sleep if that’s part of your plan (more on this in the next section).
  • Eat well and take it easy on the caffeine and alcohol. These substances mess with your sleep and energy levels, and can make you even more dehydrated. Instead, drink lots of water – at least 8 ounces for every hour you’re flying.

On the plane

  • Unless you’re on a red-eye, avoid sleeping for longer than a 30-minute power nap. Otherwise you could enter deep sleep and wreak more havoc on your sleep cycle.
  • During your flight and/or layovers at the airport, try not to sit still for too long. Periodically walk the aisles, and do some stretching exercises in your seat to avoid blood clots.
  • If you do sleep, keep your seatbelt buckled and visible to flight attendants so they don’t disturb you. Recline your seat or use the tray table as a pillow.
  • Take the opportunity to deplane during layovers. If there’s an opportunity to get a shower, then by all means do so. It’ll be good to stretch your legs before another grueling flight, and a shower will make you feel even better.
  • Change your phone, computer, and watch to local time.

After flying

  • Adhere to the new sleep and social schedule of your destination. Eat when others eat, and sleep when others sleep. Go to sleep if you arrived at night, and try to stay awake if you arrive during the day. If you really have to sleep, take only two hours to get rid of the worst fatigue. After waking up, take an hour’s walk in the sun to help your body get used to the change.
  • Many people take melatonin to help them fall asleep, and it’s shown to be an effective jet lag treatment. Take melatonin about 30 minutes before you want to go to bed. There’s no need to overdo it with melatonin. Studies have shown that a 0.5 mg dose is just as effective as higher ones for treating jet lag.
  • Certain sleep medications can help you sleep earlier, but remember to only use these as a last resort – they may make jet lag worse.
  • Get some sun. Sunlight is a free way to help you adjust your body clock. Spend time outside in the morning if you traveled east, or in the afternoon if you traveled west. Exercise when you’re outside to give yourself an extra energy boost. Once it’s time for bed, draw the curtains in your room and make it dark as possible.
  • In the absence of sunlight, bring a portable light therapy device to help you adjust. These devices come in many shapes and forms, from traditional-looking lamps to wearable visors, and are designed to mimic bright 10,000-lux sunlight without the UV rays. Use yours in the morning to help you wake up easier for eastern travel, and use it at night if you traveled west. You can get a larger lamp device for your home to help you adjust upon your return.
  • For extreme travel (8 time zones or more), you’re at risk of completely inverting your schedule, so you have to time your exposure to light accordingly to avoid your body confusing dawn for dusk, or vice versa. If you traveled west, avoid sunlight in the early evening. If you traveled east, wear sunglasses and avoid sunlight in the morning. In the late afternoon, take off the sunglasses and go outside or otherwise expose yourself to bright light. The charts below, from the Cleveland Clinic Journal of Medicine, suggest when a traveler should seek out light (L) or darkness (D).

jet lag plan for 9 time zones east jet lag plan for 7 time zones east

Jet lag recovery

If you’re feeling the effects of jet lag, take comfort in the fact that it will be a temporary nuisance, and it will go away on its own.

There’s a rule of thumb that the best way to get rid of jet lag is gradually over a few days. The number of days should equal the number of time zones crossed. In other words, you’ll need to adjust your body clock by one hour every day.

Besides adjusting your sleep schedule, there is much you can do to speed up the process and ensure more restful sleep at your destination.

  • Exposure to daylight at your new location can help reset your circadian clock, and it is a good idea to take a walk right after you wake up.
  • Adhere to the social schedule at your destination. Engaging in what everyone else is doing will help you get in alignment with your current time zone after trans-meridian travel.
  • Upon arriving, it’s normal to feel energized about the trip, stressed from travelling, or anxious about your meeting agenda. This can lead to insomnia on the first night, exacerbated by jet lag. To help yourself fall asleep faster, follow good sleep hygiene, watch your caffeine and alcohol intake, and avoid long naps.
  • If you have a huge presentation or are meeting the parents, it’s also normal to experience nerves no matter how prepared you are. Practice deep breathing exercises, progressive muscle relaxation, or meditation to calm your mind.
  • An unfamiliar environment can make sleep hard to come by, so make your hotel room as comfortable as possible. Bring your own sheets, a pillow, or even a stuffed animal from home. Bring diffusers that you use at home so you can make it smell the same. The eye masks or ear plugs that proved so helpful on the plane will also help you block out noise from the hallway or air conditioner. Ask for extra towels to block out sound or light from the hallway, or ask to be moved to a room further away from the elevator. Adjust the thermostat to a cool mid-60 degrees Fahrenheit.