Jet Lag: Everything You Need to Know. Causes, Symptoms and Recovery.

Jet Lag: Everything You Need to Know. Causes, Symptoms, and Recovery

The complete jet lag overview you'll ever need

If you’ve ever traveled across timezones, you might have experienced jet lag as at some point.

Jet lag comes with tiredness. You’re unable to sleep. And for days after your trip, you continue to find it hard to sleep.

What is jet lag

Jet lag is a sleep disorder. It’s when your body’s internal circadian rhythm is out of sync with your external environment after traveling across multiple timezones.

Whether you’re young or old, you can experience jet lag. Although the older you are, the harder it is to recover from jet lag.

A chief factor that influences jet lag is the number of timezones you travel.

Most people experience jet lag after traveling across at least two time zones by air.

Also, the direction of your flight has a big role to play.


Studies show that if you travel eastward, the duration of jet lag is longer. But if you travel westward, jet lasts a bit shorter.

Jet lag causes: What causes jet lag

To understand how jet lag occurs, it’s crucial to know how the circadian rhythm works. After all, all sleep disorders rise and fall on that.

The circadian rhythm is the body’s clock that influences sleepiness and wakefulness.

This clock controls a part of the brain called suprachiasmatic nucleus (SCN). The SCN influences our reactions to light and darkness.

Besides controlling the sleep and wake cycles, the circadian also affects the hormones and temperature levels in the body. 

When we travel across timezones, the SCN receives visual cues of light and darkness from the eyes. This affects the circadian timer. How?

The circadian system is not able to keep up with the speed and shift that comes with air travel across several timezones. 

And keep in mind the circadian system depends a lot on external cues.

For example, the brighter it is around us, the stronger the cue for alertness is. Our brain knows when to release melatonin based on light exposure.

So with air travel, so much happens.

With all these changes in your environment as you travel, it takes time for this master control in our body to adjust to the direction, location, and new time zone.

The process of adjusting leads to jet lag.

Related: Shift Work Sleep Disorder: Everything You Need to Know

Jetlag symptoms: how do you know if you have jet lag

So how do you know if you are experiencing jet lag?

Some of the prominent symptoms include:

Jet lag’s impact on sleep tends to persist longer if the shift in time zones is more than 8 hours.

Jet lag recovery: how to recover from jet lag

The good news is that treatment for most jet lag can be as simple and without any medicated drugs. 

People with severe jet lag symptoms may need prescribed medication.

But most people recover from jet lag with a few lifestyle changes once they are in their new location.

Let’s go over a few of the things you can do to reduce the effects of jet lag.

1. Sleep schedule before trip

One way to reduce the impact of jet lag and recover quickly is to prepare before your trip. Let me explain.

If you will be traveling to a new timezone, modify your sleep schedule a few days before so it aligns with the time where you’ll be going. 

This is especially helpful if you’ll be staying longer at this new location. For example more than a week. 


It helps your body to gradually transition to the time change. If your trip is less than a week, this might not be that impactful.

2. Light exposure

Sunlight plays a critical role in adjusting our circadian system. 

More exposure to sunlight alerts our brain and keeps us awake. And less sunlight exposure can induce sleepiness.

If you travel across timezones, the new location’s daylight time may be different. You’ll need to adjust to this new time so get more natural exposure to sunlight.

What if you can’t get sunlight exposure? A good alternative is a light therapy.

Light therapy helps to simulate sunlight to the eyes and align our sleep to the internal clock.

But that’s not all. Studies have shown that light therapy can improve mood and reduce depression.

One study found that as little as 20 minutes of light therapy can make a difference in mood, and make you feel better.

Light can help in adjusting to the new timezone. In this case, choosing the right bedroom light will be key.

3. Exercise

No matter the purpose of your traveling, be it for vacation or work purposes, making time for exercising can help reduce jetlag symptoms.

This is perhaps the well-known shortcut if you want to fall asleep naturally

Researchers at the University of California and Arizona State University looked into this. They found that exercises help to counter the negative effects of restlessness and have a more restful sleep. 

If you can, add regular outdoor exercises to your routine.

Otherwise, try some indoor exercises that require no equipment or simple bedtime stretches.

This helps to boosts serotonin in the brain. Serotonin is a precursor of the brain’s signal to wind down

4. Melatonin

Sleep is a result of the increase in melatonin concentration on our body, among other things.

When melatonin increases, it signals to our body that our biological nighttime is starting. A decrease in melatonin signals that nighttime is ending.

It’s not surprising that melatonin is one of the most researched benefits of melatonin is in the area of eliminating jetlag. 

Taking melatonin is a good way to get rid of jet lag symptoms including extreme tiredness, and it’s associated wakefulness. 


In one study, researchers in New Zealand observed 20 volunteers with experience of transcontinental flights through at least 5 time zones. 

Participants took 5 mg melatonin capsule (others a placebo) once a day on pre-flight days 1-3 (between 1000 h and 1200 h), during flight, and once a day for post-flight days 1-3 (between 2200-2400 h)

The findings showed that participants who took melatonin reported that they were less tired during the day. 

Also, melatonin enabled them to adapt more quickly to normal sleeping hours and patterns. It also helped to regain their usual energy levels

Researchers in France also found that melatonin had a positive effect on alleviation jet lag in 37 participants who travel intercontinental flights.

These participants usually experience subsequent discomfort after an eastward journey. Melatonin had a huge impact. 

5. Sleep hygiene

Sleep hygiene refers to the environment and behaviors surrounding our bedtime.

If you combine all the activities you do right before sleep, you’ll have a good picture of what your sleep hygiene is. 

Some of the ways you can improve sleep hygiene include:

  • Temperature: Set the room to the right temperature. If temperatures are high, we are more awake. If temperatures are low, we are more sleepy.
  • Bedroom light: Choose dimmer lights at night. Several studies have shown that bedroom light can affect sleep quality. Blue light stimulates attention and energy – something you don’t need when you want to fall asleep. 
  • Noise: avoid all loud noises if you want to sleep better. Most people cannot sleep in loud environments and use white noise to block it out.
  • Sleepwear and bedding: Avoid synthetic material because they hold more heat and make you warmer. Choose breathable materials. You can choose to sleep naked if it helps you cool down.

6. Caffeine

Caffeine can help reduce the effects of jetlag symptoms. Especially the ones that relate to concentration and cognitive performance 

A group of researchers reviewed 13 randomized trials. The trials were with people experiencing jet lag and shift-work disorder. 

The researchers found that participants who took caffeine improved:

  • attention
  • concept formation
  • reasoning
  • memory
  • orientation
  • perception

Another study looked into the impact of slow-release caffeine and melatonin after an eastbound flight. 

The findings show caffeine can help synchronize hormone rhythms four days after travel. Caffeine can also help reduce daytime sleepiness.

Related: How to Stay Active While Traveling to Avoid Weight Gain.


Jet lag symptoms: How long does jet lag last?

In general, jet lag lasts for a few days until you have adjusted to your new location’s time. 

Jet lag recovery depends on a few factors like age and number of timezones.

Younger people need less time to recover from jet lag symptoms compared to older people.

Also, traveling eastward makes if more difficult to adjust to new times zones than if you travel westward.

This is because eastbound travel involves speeding up your internal clock and sleep cycle.

Air travel across timezones tends to be at higher altitudes. This can increase the time you need for jet lag recovery.

Higher altitudes impact air pressure and quality and oxygen levels in the body and hence the circadian system.


While you may not be able to prevent jet lag at all, there are certain things you can do to improve your recovery and reduces the impact.

On top of all the tips we’ve discussed, general lifestyle improvement can help as well. As you fight jet lag, avoid drinking excessive amounts of alcohol.

If you can take a few days off work, do that. You’ll need less stress and more rest to help recover from jet lag