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What is Jet Lag? Symptoms, Causes, and Treatments

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If you’ve ever traveled internationally, you’ve likely experienced jet lag, a temporary sleep disorder in which the body’s internal clock falls out of sync with its surroundings. It’s a disorienting sensation that can take several days to shake, especially if you don’t know how to treat it.

But that’s what I’m here for! In this guide, I’m going to give you the full skinny on jet lag, from what it is, what its symptoms are, how to cure it, and much, much more. So, buckle up and get ready to take off into the dizzying world of jet lag.

What is Jet Lag?

As I mentioned up top, jet lag is a temporary sleep disorder that often occurs after traveling over several time zones in quick succession. (1) The disorder can cause feelings of tiredness, nausea, confusion, and grogginess. Though the symptoms can be severe, they generally wear off after a few days, or at least until one’s internal clock gets realigned with its new surroundings.

Therefore, any discussion of jet lag really has to begin with a look at the body’s internal clock.

The Internal Clock

Every individual has their own internal clock, sometimes referred to as the “master clock,” which is powered by a group of approximately 20,000 nerve cells in the suprachiasmatic nucleus in the hypothalamus. These nerves use different external cues (like daylight and meal times) to send signals of alertness and sleepiness to the body. (2) So, if you maintain a consistent routine from day to day, your body will get used to the schedule and establish a strict set of internal rhythms to support it.

Think of your master clock as a stern maestro. She’s carefully selected the members of her orchestra and learned how to conduct its moving parts to keep things running in perfect harmony. The ensemble practices every day, has their sheet music memorized, and understands how the music is meant to ebb and flow.

Now, imagine how the maestro might respond if you kept all the players the same, but gave them new instruments and sheet music. And then demanded that they perform a concert that very night. Chaos would likely ensue as the orchestra attempted to restore order to the well-oiled machine. There would need to be additional rehearsals to master the new movements. Undoubtedly, the players would groan and complain about the changes, until they, too, became second nature.

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Jet lag is powered by disruptions in the internal clock caused by traveling across many time zones.

And that’s basically what’s going on in your body when you travel far away from your home time zone. The interior mechanics get thrown way out of whack, leaving you feeling foggy and discombobulated.

If you’re a New Yorker visiting Tokyo, for example, your internal clock will still be using Eastern Standard Time cues when you first arrive, even though you’re quite literally 14 hours ahead in Japan Standard Time. That’s why you might feel sleepy while the folks around you are up and ready to start the day or why you might want to devour a four-course meal at two in the morning.

Thankfully, the effects wear off once your body has fully acclimated to the new time zone. For that reason, jet lag is categorized as a temporary sleep disorder, and a highly common one at that, with over 200,000 cases reported annually in the United States alone.

Jet Lag Symptoms

So, what exactly does jet lag feel like? As with any type of disordered sleeping, the symptoms can vary a lot depending on the individual, but some of the most common ones include:

  • Disturbed sleep, mostly in the form of insomnia or excessive sleepiness.
  • Daytime fatigue, especially at times in which you’re normally energized or alert.
  • Difficulty focusing or concentrating on the task at hand.
  • Stomach issues, which could include constipation, diarrhea, or nausea.
  • A general sense of huh? powered by fogginess and confusion.
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Sound like fun, don’t they?!

It’s worth noting that jet lag symptoms won’t always be so extreme, especially if you’re only traveling a few hours ahead or behind your normal zone. A general rule of thumb is that the farther ahead you go, the worse your symptoms will be. This is because you’ll be advancing your clock as opposed to delaying it, a phenomenon that also occurs when we “spring forward” during Daylight Savings Time.

Now that we’ve talked about the major symptoms, let’s get into a few treatments for jet lag.

How to Treat Jet Lag

Though there’s no way to fully cure jet lag (sorry!), there are a few tricks you can employ to soften its worst effects.

  • Since the internal clock is influenced most heavily by the sun, it’s important to expose yourself to as much daylight as you can when you first arrive at your destination. It’s totally fine to take a quick cat nap after your flight, but it’s crucial to get up and move.
  • You’ll also want to hydrate a ton on the plane ride over. While you might be tempted to grab a glass of wine to fuel some shut-eye in the sky, it’s actually much better to skip the alcohol all together and down copious amounts of H2O. Fatigue is directly tied to dehydration, so loading up on the watery good stuff will help you immensely once you land.
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Though not complete cures, these tips should help ease the worst effects of jet lag.
  • Try to get into the rhythms of your new zone as quickly as possible. This may mean eating before you’re hungry or staying up late even if you’re exhausted. Though annoying in the short term, it’ll help a great deal in the long term.
  • If you can, book an overnight flight that arrives in the morning. That way, you can sleep on the plane and start a new day as soon as you land. You’ll still feel some exhaustion, but you’ll be able to get into the swing of things much faster.

Curious to know more about jet lag? Then take a look at some of the most commonly asked questions we get about it here at Sleepopolis.

Jet Lag FAQs

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Well that’s all she wrote! For more travel resources, make sure to check out our guide to the Best Travel Pillows as well as our tips for catching Zzz’s in the airport.


  1. Choy, Mary, and Rebecca L Salbu. “Jet Lag: Current and Potential Therapies.” P & T : a Peer-Reviewed Journal for Formulary Management, MediMedia USA, Inc., Apr. 2011.
  2. Bernard, Samuel, et al. “Synchronization-Induced Rhythmicity of Circadian Oscillators in the Suprachiasmatic Nucleus.” PLoS Computational Biology, preprint, no. 2007, 2005.
Cody’s our staff editor here at Sleepopolis, so manages our fantastic editorial team and brings an expert eye to the written content across our social media, news vertical, and blog. A typical day could include editing an extensive piece on sleep paralysis, popping off a quick Instagram post about the benefits of daytime napping, drafting an informative guide to nightmares, or creating a fun round-up of the best cooling mattresses on the market. TL;DR there’s no such thing as a typical day at Sleepopolis and that’s exactly how Cody likes it. His work has appeared online for Esquire, Next, LOGO TV, Fandom, Citylife, The Manual, and more.