Jet Lag: Symptoms, Causes, and How to Cope

Did you know that jet lag happens when people travel rapidly across time zones? In fact, it also happens when your sleep is disrupted. Read on to learn more about this condition.
Jet Lag: Symptoms, Causes, and How to Cope

Last update: 04 November, 2022

Jet lag is also known as time zone change syndrome or desynchronosis. It occurs when people travel rapidly across time zones or when their sleep is disrupted. It’s a physiological condition resulting from a disruption in the body’s circadian rhythms. Therefore, it’s considered a circadian rhythm disorder. Long-distance plane travel is infamous for being inconvenient and uncomfortable. 

Due to the overwhelming logistics of check-in and the stress of security lines, travel is harsh. Most importantly, the hours stuck in a confined space, many people find extended plane trips to be seriously taxing. Jet lag frequently contributes to the physical burden of long flights. It refers to the misalignment of your body’s internal clock with the local time at your destination. 

This phenomenon often occurs when flying across three or more time zones. It can dramatically throw off your sleep. It causes other bothersome symptoms that persist for days or even weeks after a flight. Whether you’re traveling for business or pleasure, the time zone change syndrome can negatively impact your trip. Symptoms tend to be more severe when traveling eastward compared with westward.

Jet lag can occur when your sleep-wake patterns are disturbed. A person may feel drowsy, tired, irritable, lethargic, and slightly disoriented. Furthermore, it can result from traveling across time zones or from doing shift work.

T ravelers should know about the psychological condition, including its symptoms, causes, and ways to cope. This can make long-distance trips more pleasant and less disruptive to sleep and overall health.

What’s jet lag?

It’s a circadian rhythm sleep-wake disorder. It occurs when your 24-hour internal clock, known as your circadian rhythm, doesn’t match the local day-night cycle. In fact, under normal circumstances, a person’s circadian rhythm aligns with daylight, promoting alertness during the day. It also promotes sleep at night. This internal clock synchronizes with the 24-hour day to promote quality sleep, as well as physical and mental health. 

A person’s geographic location affects their circadian rhythm since sunrise and sunset occur at different times and locations. The time zone change syndrome happens when a person travels east or west across three or more time zones. For example, Los Angeles to New York travelers. If you fly from Los Angeles to New York and arrive at 8 p.m., your body operates differently. It might still operate as if it’s in Los Angeles at 5 p.m. This phenomenon can cause you to stay up later than you’d like and sleep at odd hours. Similarly, it also causes you to feel more tired than usual, among other symptoms. The more time zones a person crosses in a short period, the more severe the symptoms will be.

Jet lag is related to a disruption in activity. It’s also related to a lack of synchronization in the brain cells of two parts of the brain. The older a person is, the more severe their symptoms will be. The older you are, the longer it’ll take your body clock to get back into sync. C hildren usually have milder symptoms and recover faster.

An image of travellers at airport.


The most common symptoms of jet lag include:

  • Sleeping problems. It may be hard to fall asleep when you want to or you may wake up earlier than planned. The physiological condition can also cause sleep to be fragmented.
  • Daytime sleepiness. The condition frequently causes you to feel drowsy or tired during the day.
  • Impaired thinking. You may experience problems with attention or memory or simply feel like your thinking is slowed.
  • Hampered physical function. Your body may feel tired. Thus, peak physical performance may be affected, which is especially notable for traveling athletes.
  • Emotional difficulties. Some people with the condition feel irritable. Recent evidence indicates that it can exacerbate mental health problems, such as mood disorders.
  • General malaise. The time zone change syndrome may make you feel malaise. In other words, a general feeling of discomfort, illness, or uneasiness.
  • Stomach problems. It can also induce gastrointestinal problems like reduced appetite, nausea, or even constipation and irritable bowel syndrome.
  • Sleep paralysis and seizures. In rare circumstances, the phenomenon may impact sleep architecture. This, in turn, increases the risk of sleep paralysis and nighttime seizures.

These symptoms arise after long flights to different time zones. Disrupting your circadian rhythm impacts how and when your body produces hormones that affect sleep and other bodily processes. People with the condition experience one or more of the symptoms listed above.

Symptoms can begin immediately or set in a few days after arrival.  Many people sleep well the first night after a flight only to encounter sleep problems in the following days. Jet lag lasts anywhere from a few days to a few weeks. In general, symptoms persist for one to two days per time zone crossed. Still, the duration of symptoms varies depending on the person and their trip details.

Can this physiological condition have long-term consequences?

Fortunately, jet lag is usually a short-term problem. It goes away once you adjust your body’s circadian rhythms to the local time. For people in the world who frequently take long-distance flights, such as airline pilots, flight attendants, and business travelers, it becomes a chronic problem. 

A chronically out-of-sync circadian rhythm can create persistent sleep problems that may lead to insomnia. A healthy internal clock is important for the body’s overall health. Thus, chronic circadian rhythm disruption may elevate the risk of serious disorders like diabetes and depression. This disruption can also elevate the risk of some types of cancer.


Lane travel that crosses three or more time zones causes jet lag. Symptoms may be more pronounced as more time zones are crossed. Most people find that the condition is worse when traveling east than it is when traveling west. Besides, its severity highly differs based on the direction of travel. It’s generally easier to delay your internal clock than advance it. 

It simply doesn’t occur on north-south flights that don’t cross multiple time zones. Not everyone who takes a long-distance flight gets the time zone change syndrome. Multiple factors influence the likelihood and severity of it. Check them out:

  • Trip details. Many specifics of a trip can affect it. For instance, the total distance, amount of layovers, time zones crossed, and direction of travel. Local daylight hours and length of time at the destination also affect it.
  • Arrival time. When you arrive at your destination, your circadian rhythm may be affected. For eastward travel, some evidence indicates the phenomenon reduces with afternoon arrivals compared to those in the early morning.
  • Past history of the conditions. People who’ve previously had jet lag are prone to have it again.
  • Sleep before traveling. Poor sleep in the days leading up to a flight isn’t good. It increases a person’s propensity for the psychological condition after traveling.

As there are many factors involved, it’s hard to know exactly who will develop the syndrome. It’s also hard to know how severe it will be and how long it will last. However, it’s common for at least a mild case to occur when crossing more than three time zones during flight.

More causes

Are you ready to check out even more must-read causes of jet lag?

  • Age. As we mentioned above, a person’s age may play a vital role in jet lag, although studies found mixed results. People over 60 experience circadian changes that can make it harder for them to recover from the physiological condition. Nevertheless, some research in pilots found it to be much worse in younger people.
  • Stress. Being stressed out can keep the mind and body on edge in ways that interfere with sleep. Hence, it makes it much harder to cope with time zone change syndrome.
  • Use of alcohol and caffeine. Many people drink alcohol and coffee during flights. Sadly, these substances affect the brain in ways that can disrupt sleep. The World Health Organization (WHO) points out that drinking alcohol or caffeine during or before the flight may worsen symptoms. For one thing, these can both add to dehydration.
  • Altitude sickness, oxygen, and dehydration. The pressure in an airplane’s cabin is lower than the pressure at sea level. Thus, the amount of oxygen reaching the brain is lower when people fly. This leads to lethargy and a higher risk of more severe jet lag symptoms. Researchers found that people traveling on commercial flights face changes in air pressure. This leads to discomfort and symptoms that resemble those of altitude sickness.
  • Individual variation. For reasons that aren’t fully understood, there’s a variation. Some people are more likely to experience circadian rhythm disruption with long-distance flights than others.

Difference between jet lag and travel fatigue

It’s normal to feel wiped out after a long day of traveling. While this can be confused with jet lag, it’s often a result of travel fatigue. Travel fatigue includes symptoms that arise because of the physical toils of travel, such as tiredness and headaches. Airplane cabins, which have cool, dry, low-pressure air, can cause dehydration and susceptibility to respiratory problems. 

Air pressure changes can lead to bloating, and long-term sitting can cause leg swelling. It’s often difficult to sleep upright in an airplane seat, especially with in-flight interruptions. Therefore, getting quality rest in transit can be challenging. All of these factors contribute to feeling exhausted after a long flight, though this is distinct from jet lag. 

Unlike it, travel fatigue doesn’t involve circadian rhythm disruption. For that reason, travel fatigue usually goes away after a good night’s sleep. Time zone change syndrome can persist for days or weeks until a person’s internal clock becomes realigned. It’s possible to have both travel fatigue and jet lag after a long-haul flight. Nevertheless, the latter is far more likely to cause lasting and extensive symptoms.

Practical tips for reducing it

A number of practical tips for before, during, and after your flight help reduce sleep disruptions and travel fatigue. This way, you’ll surely make the most of your trip, whether it’s a vacation or business trip.

Before traveling

  • Schedule the first days of your trip. Make sure to give yourself time to sleep and follow your plan for light exposure. Build buffers into your schedule just in case you feel sluggish. If possible, arrive days in advance of an important meeting or event so you have time to acclimate.
  • Minimize travel stress. Don’t wait until the last minute to pack or leave for the airport. Being in a rush can heighten stress and make your travels more difficult.
  • Get quality sleep. Focus on getting quality rest for at least a few nights before your trip. Consequently, you won’t be already sleep-deprived at the beginning of the trip.

During the flight

  • Stay hydrated. Drink water to replenish fluids and counteract the dehydration that can occur during the flight.
  • Limit alcohol and caffeine. Reduce alcohol and caffeine intake on board or don’t drink them entirely.
  • Eat smart. Reduce the risk of digestive problems by eating healthy and light. Opt for fruits and vegetables over heavy, calorie-rich, fatty snacks.
  • Stand up and move. Blood clots and stiffness can occur if you’re seated for too long. Walking, standing, and gently stretching a few times during the flight may reduce these risks.

After arrival

  • Exercise. Find time for a walk or other light physical activity. Exercising outside to receive appropriately timed daylight exposure will help recalibrate your circadian rhythms.
  • Limit alcohol, caffeine, and heavy meals. Avoid excessive caffeine, alcohol, or heavy and calorie-rich meals.
  • Nap with caution. Avoid the temptation to take a long nap. Try to keep naps less than 30 minutes and only nap eight or more hours before your planned bedtime.
An image of stressed tired woman on couch.

How to prevent it

Jet lag can have ruinous effects on a vacation, business trip, or athletic competition. As a result, travelers of all types strive to minimize its effect. What’s the key to preventing it? Quickly realign your circadian rhythm to synchronize with the time zone of your destination. Until you achieve it, there are steps to manage symptoms.

For very short trips, avoid it by scheduled activities keeping your circadian rhythm aligned with your home time zone. For instance, sleep. This way, you avoid circadian disruption both during the trip and after you’ve returned home. For travel lasting more than a few days, minimizing desynchronosis requires acclimating to your destination day-night cycle. Check out these methods of reorienting your circadian rhythm:

Melatonin and sleep aids

Melatonin is a hormone that the body produces. It helps to both make you feel sleepy and also governs your circadian rhythm. Melatonin is normally produced in the evening, a few hours before bedtime. Even so, this schedule can get thrown off by the time zone change syndrome.

Pre-adjusting your internal clock

Methods of preventing the condition include modifying your sleep schedule in the days leading up to your trip. This way, upon your arrival, there’s less discrepancy .When you arrive at your destination, there’s less discrepancy between your circadian rhythm and the local time.

Creating a plan for overcoming it

The optimal plan to avoid the time zone change syndrome depends on many factors. For example, flight direction, the number of time zones crossed, and how long you’ll remain at your destination. Other factors include your schedule and obligations during your trip.

In short, taking these factors and tips into account will help you reduce jet lag. Doctors, travel nurses, or sleep specialists may be available to help you prepare a plan for managing it. Several online resources and apps can help you generate tailored schedules to help reduce it on your trips.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.