What Causes Jet Lag and What Can You Do to Manage and Prevent It
Medically reviewed by Amelia MacIntyre, DOMedically reviewed by Amelia MacIntyre, DO
Jet lag occurs when you travel across time zones, and experience challenges adjusting to new sleep and wake times. It can make it difficult to fall or stay asleep, wake up in the morning, and feel rested during the day. Jet lag typically happens when you cross three or more time zones in a relatively short period.
Jet lag is temporary, and there are ways to manage and prevent it.
Learn about jet lag, its causes, what it feels like, how to prevent and treat it, and more.
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How Jet Lag Affects Your Body Clock
Your body's internal clock (circadian rhythm) regulates your sleep and wake times in response to light and dark cues. Traveling across time zones means the sun will rise and set at a different time than you're used to. For example, if you travel six time zones east (e.g., New York to Paris), the sun will rise and set six hours earlier.
Since your body clock is regulated by light and dark, flying across multiple time zones causes an abrupt shift that your body is not equipped to adjust to immediately.
What Does Jet Lag Feel Like?
Jet lag symptoms vary depending on how far you've traveled and your body's circadian rhythm. It can make you feel tired, exhausted, or similar to being sick.
In addition to feeling tired, other symptoms of jetlag include:
Brain fog (i.e., feeling unable to think clearly)
Difficulty falling asleep at night, staying asleep, or waking up in the morning
Digestive issues (e.g., constipation or diarrhea)
Mood changes and difficulty regulating your emotions
Physical fatigue
What Causes Jet Lag?
Jet lag is caused by the difference in your body's internal clock and your new location's light and dark hours.
That difference is one hour for each time zone crossed. For example, traveling from California to New York (three time zones apart) would mean being physically located in New York with a circadian rhythm set to California, three hours behind.
Your Clocks Don’t Align
When you travel across time zones, your body's clock remains synced to your previous time zone. It's like setting a bedtime and alarm clock based on a different schedule. The mind, body, and internal clock may take several days to adjust to the new time zone—typically one to 1.5 days for every hour crossed.
While the actual cause of jet lag is a shift in sleep and wake times, other factors can make the symptoms feel better or worse.
Sleep Timing
One strategy to prevent jet lag is slowly shifting to a new sleep schedule before traveling. When traveling east, for example, slowly move bedtime and wake time earlier. Conversely, when traveling west, slowly move bedtime and wake time later.
Sunlight
Since light cues regulate the sleep and wake cycle, natural sunlight can help you adjust to a new schedule in a different time zone. Sunlight is the most powerful environmental tool to help you become more awake in the morning and earlier in the day.
Experts recommend opening the curtains first thing in the morning and then going outside in the sun as early as possible.
Travel Fatigue
Fatigue caused by your travel experience can worsen jet lag symptoms. The physical and mental demands that often accompany travel can contribute to jet lag. Travel fatigue can be prevented with the following strategies:
Planning ahead
Resting before and after travel
Getting proper nutrition and drinking plenty of water
Altitude Sickness
Traveling across time zones can also include changes in altitude, which can cause you to become ill. Some symptoms of altitude sickness are similar to those of jet lag, including feeling tired, exhausted, ill, and having difficulty sleeping.
The combination of altitude and changing time zones can worsen symptoms. Like jet lag, the symptoms of altitude sickness typically go away after a few days.
Dehydration
Travel, especially by plane, increases the risk of dehydration. Symptoms of jet lag become worse with dehydration. Drinking water while traveling is vital to prevent dehydration and jet lag.
Coffee and Alcohol
Coffee and alcohol are both dehydrating, so they can increase symptoms of jet lag. However, caffeine may help treat jet lag symptoms. When using caffeine for jet lag, consume it only in the morning to prevent difficulty sleeping at night. And be sure to drink water, too.
Other Factors That Affect Jet Lag
Physical activity and exercise can help prevent or alleviate jet lag symptoms and improve sleep quality. Getting your body moving in the morning while in the new time zone can help you sleep better and adjust faster.
Your thoughts and perceptions of the experience can also make a difference. Focusing on the symptoms will make them feel worse. Holding on to a belief that certain behaviors will help can lead to doing those things, like drinking plenty of water, taking a walk in the morning sunlight, and then feeling better.
Why Is It Harder to Travel From West to East?
Traveling from west to east is more challenging than traveling east to west because the body's internal clock adjusts to time zones faster when traveling west. More specifically, you can adapt 1.5 hours a day when traveling west and only an hour per day when traveling east.
For example, traveling three time zones away will take about two days to adjust when traveling west and three days when traveling east. For most people, it tends to be easier to stay up late at night and sleep in than to fall asleep and wake up earlier.
Ways to Prevent Jet Lag
One of the best ways to prevent jet lag is to slowly shift to the new sleep and wake schedule before travel, making the transition easier when you arrive in the new time zone. Other options to prevent jet lag are to drink plenty of water, get sunlight exposure in the morning after arriving, and exercise in the morning.
How Jet Lag Is Treated
Jet lag typically goes away after a few days when your body has adjusted to the new time. Most people don't need medical treatment for jet lag. Lifestyle choices such as sticking to scheduled sleep and wake times and using light and dark as tools to regulate sleep patterns can help with the adjustment phase.
Some experts recommend melatonin for temporary use to treat jet lag. However, its effectiveness is unclear, and there are associated risks.
How Long Does Jet Lag Last?
Jet lag is based on individual factors, like your typical sleep schedule and how many time zones you've traveled. So, if it typically takes one day to 1.5 days to adjust to each time zone traveled, traveling four time zones away would take four to six days to adjust. It can take weeks to recover fully, especially when traveling across more time zones.
When to Contact a Healthcare Provider
Jet lag symptoms typically go away on their own as your internal clock adjusts to the new time zone. If symptoms worsen or last longer than two weeks after traveling, it is important to seek medical care to alleviate symptoms and rule out any other symptom causes.
Summary
Jet lag is caused by traveling across time zones faster than the body can adjust to the new sleep and wake schedule. Symptoms of jet lag include feeling tired, being physically exhausted, and feeling sick. Light and dark cues regulate your internal body clock, so sunlight in the morning and darkness before bed can help to make the shift easier.
It can also help to shift to the new schedule before travel, drink plenty of water, and be physically active in the morning when in your new location. Jet lag typically does not need to be treated, but it is important to see a healthcare provider if the symptoms worsen or last longer than two weeks.
Read the original article on Verywell Health.
