Jet Lag: Definition, Causes, Symptoms, and Risk Factors

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- Updated by Judy Mullis, MS, RD, Nutritionist

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Jet lag is daytime fatigue, drowsiness, or an inability to sleep on time. A cause of jet lag is when your sleep pattern is changed when entering a new timezone during your travels. Typical jet lag symptoms include fatigue, drowsiness, an unwell feeling, stomach problems, and in rare cases, sleep paralysis and seizures. Jet lag affects the body with drowsiness, inability to concentrate, and indigestion. NMN supplements have become an important tool for travellers looking to increase energy, focus and cognition.

Jet lag is moderately common, affecting frequent travelers more than people who do not fly. The risk factors of jet lag include how many time zones are crossed if you’re traveling east, a frequent flier, and an older adult. Treatment of jet lag includes light therapy, sleeping pills, caffeine, and melatonin pills.


What is Jet Lag?

Jet lag is when you become fatigued or tired when your sleep pattern is changed or disrupted after a long flight, according to the NHS in 2020. Jet typically does not require medicine, and symptoms improve in a few days as you adjust to the timezone of your new location. Symptoms of jet lag typically include trouble sleeping at night, fatigue, trouble staying awake in the daytime, and concentration difficulties.

How common is Jet Lag?

Jet lag is moderately common; however, much about jet lag remains undefined. At least 70% of surveyed business travelers said that jet lag symptoms affected them fairly often, according to UpToDate in 2022. At this point in time, there needs to be more research to say clearly which age groups and genders jet lag affects the most. To understand what is jet lag, it’s essential to know that jet lag affects everyone differently. Older adults, however, may experience jet lag symptoms.


What does Jet Lag feel like?

Jet lag feels like mental exhaustion during the day, insomnia at night, an overall unwell feeling, and difficulties staying alert, according to the Mayo Clinic in 2022. To understand how long does jetlag last, it’s essential to know that jet lag symptoms are temporary and last upwards of only a few days.

What are the Causes of Jet Lag?

Jet lag causes a mismatch between a person’s regular sleep routine and a sudden transfer to a new timezone (typically via flight). Jetlag is classified as a temporary sleep disturbance that may affect people traveling over three or multiple time zones.

What are the Symptoms of Jet Lag?

The symptoms of jet lag, and the subsequent jet lag meaning in how it affects the body and mind, are listed below.

  1. Sleeping problems - Sleeping problems include struggling to sleep on time, waking up too early, or insomnia.
  2. Daytime sleepiness - Feeling tired during the day, or being unable to stay awake are the effects of daytime sleepiness.
  3. Impaired thinking - Impaired thinking includes trouble with memory and attention span.
  4. Hampered physical function - Hampered physical functions include body tiredness, and feeling at a person’s physical peak.
  5. Emotional difficulties - Emotional difficulties include being moody or irritable.
  6. General malaise - An overall unwell feeling or unease defines general malaise due to jet lag.
  7. Sleep paralysis and seizures - Although rare, sleep paralysis and seizures can cause you to be unable to move while sleeping, and your muscles to convulse.
  8. Stomach problems - Stomach problems include indigestion, nausea, and diarrhea.

1. Sleeping problems

Sleeping problems are a symptom of jet lag, including having trouble falling asleep during the night, waking up earlier than expected, or struggling to stay awake when you want. Jet lag may also cause your sleep to become disrupted, and you may be unable to stay asleep for long periods. Sleeping problems are a symptom of jet lag as your body’s sleep patterns are not yet adjusted to the new time zone, although let lag treatment is not usually necessary. 

2. Daytime sleepiness

Daytime sleepiness due to jet lag can cause excessive tiredness or fatigue during the day. Daytime sleepiness is one of the symptoms of jet lag, as traveling across time zones disrupts the body’s sleeping patterns. 


3. Impaired thinking

Impaired thinking is a symptom of jet lagged, and may cause a person to feel like their mind has slowed down, they can’t concentrate, and they may have difficulty with their memory and attention span. Impaired thinking is a symptom of jet lag because the body’s sleep-wake cycle is disrupted, which may lead to a loss of sleep (or sleep deprivation), and can affect mental processes that need quality sleep to be maintained, such as memory and attention.

4. Hampered physical function

Hampered physical function or physical fatigue is a symptom of jet lag and includes an overall tired feeling, and a person not feeling at their peak performance. Hampered physical function is a symptom of jet lag due to disrupting the body’s sleep-wake cycle. To learn how to get over jet lag, it’s essential to know that trying to sleep on time, and avoiding caffeine and alcohol are some of the best ways to get over it quickly.

5. Emotional difficulties

Emotional difficulties, such as mood disorders and general irritability, are a symptom of jet lagged meaning as jet lag causes sleep deprivation. When a person is sleep-deprived due to jet lag, it can cause an imbalance in their mood.

6. General malaise

General malaise, or a jet lag headache, is when a person feels generally unwell, uncomfortable, ill, or uneasy due to jet lag. Jet lag causes general malaise as the change in time zones disturbs the body’s sleeping pattern.

7. Sleep paralysis and seizures

Sleep paralysis and seizures are highly rare as jet lag symptoms, and include being unable to move while awake, or having the muscles seize up due to certain types of electrical activity in the brain. Sleep paralysis and seizures help us understand what does jet lag mean, as these symptoms can uncommonly be triggered by a severe disruption in a person’s normal sleep cycle or severe sleep deprivation.

8. Stomach problems

Stomach problems are a symptom of jet lag, and include effects such as indigestion, nausea, and diarrhea. Stomach problems are a symptom of being jetlagged as a disruption in the body’s sleep-wake cycle can affect the body’s physiological processes, such as metabolism.


When Do Jet Lag Symptoms Usually Occur?

Jet lag symptoms usually occur 24-48 hours after flying across at least 2-3 time zones. If a person travels farther, the symptoms are likely to be more significant and can help us define what does jet lag feels like. Mild jet lag with minimal travel will likely feel like minor fatigue. Major jet lag with lots of travel may feel like excessive fatigue, weakness in the body, and other symptoms.

What are the Risk Factors of Jet Lag?

The risk factors of jet lag are listed below, and help us define what is jetlag.

  1. The number of time zones crossed - The more time zones that are crossed, the more likely you will feel jet lag.
  2. Flying east - Fling east causes you to lose time while traveling, making the change in time zones larger.
  3. Being a frequent flier - People who travel frequently are at more risk for jet lag.
  4. Being an older adult - Older adults are at more risk as they recover more slowly from timezones changes.

1. Number of time zones crossed

Jet lag time zones

The number of time zones crossed is a risk factor for jet lag as the time zones affect your circadian rhythms (sleep cycle). The more time zones that are crossed, the more significant this change is, and it helps us understand whats jetlag.


2. Flying east

Flying east is a risk factor for jet lag as you lose time while flying in this direction, making the time change more significant and noticeable. A large gap in time zones that are different from your body’s sleep patterns is one of the main factors in what causes jet lag.


3. Being a frequent flier

People who frequently fly, such as pilots, flight attendants, and business people, will experience jetlag more frequently due to traveling through time zones frequently. This puts them at more risk for jet lag.

4. Being an older adult

Being an older adult is a risk factor for jet lag, and helps us determine what does jetlag feel like, as older adults recover less quickly. When flying and after landing, older adults may feel the effects of travel more as their metabolism and bodily functions are more sensitive to environmental changes.


What are the Complications of Jet Lag?

The complications of jetlag include auto accidents. Jet-lagged people are drowsy, and more likely to cause accidents while driving. This gives us a fair jet lag definition, and helps us understand how jet lag affects the body and brain.

How does Jet Lag affect the Body?

The body is affected by jet lag, and jet lacked symptoms through fatigue during the daytime, weakness in the body, drowsiness, and stomach sensitivities. This is because the sleep patterns, or circadian rhythms in the body, are out of sync with the changed time zone.

How does Jet Lag affect the Brain?

The physical effects of jet lag on the brain include memory and learning problems, according to Science Daily in 2010. The physical effects of jet lag on the brain, especially chronic jet lag, can cause fewer neurons to be made up to a month after traveling stops. This causes trouble remembering things, and learning new tasks, and sheds light on what does jet lagged feel like in the brain.

How does Jet Lag affect Lifestyle?

Jet lag affects lifestyle by affecting a person’s mood, concentration, and physical and mental performance. That means you may not perform at your best when your travels have concluded, and help us understand whats jet lag.

How is Jet Lag being Diagnosed?

A diagnosis for jet lag usually is not needed, according to Medicine Net in 2022. If a person feels jet lag symptoms and what does jet lag feel like, they most likely have it. If a person’s jet lag is severe or doesn’t reduce after a few days, they should consider seeing a doctor.

How is Jet Lag Prevented?

There are several ways to prevent and lower the risk of jet lag, such as slowly adjusting your sleep schedule to accommodate the new time zone before leaving, according to Mayo Clinic in 2022. For example, you could try sleeping earlier in one-hour increments if traveling east. If you are traveling west, try sleeper later in one-hour increments. You can also sleep as much as possible before you travel, as being well-rested will help reduce the feelings of jet lag. Staying hydrated also helps with jet lag recovery, as being dehydrated can exacerbate the feelings of jet lag. In addition, avoiding alcohol and caffeine can help your body retain water and function better to counteract jet lag.

What are the Treatments available for Jet Lag?

Several treatments for jet lag include light therapy, sleeping pills, caffeine, and melatonin, according to Mayo Clinic in 2022. Light therapy is sitting before a bright light source, such as the sun or a lamp. Using light therapy when the sun is up in your new time zones will encourage your internal sleeping patterns to reset. Sleeping pills to encourage sleeping on time in a new time zone can help your sleeping patterns adjust more quickly. However, sleeping pills have side effects, such as nausea, amnesia, confusion, and drowsiness in the morning. Caffeine is a treatment for jet lag as it can encourage a person to remain awake during daylight hours. However, using it after and not during travels is recommended as it dries out the body and may aggravate jet lag symptoms. Melatonin can be used as a medicine to encourage sleep as it helps cue the body for rest as a sleep aid. These jet lag treatments can help us better understand ways to mitigate jet lag and how long does jet lag last from europe or other countries. The more significant the gap in time zones, the longer the jet lag symptoms will last.

How Does Melatonin Help With Jet Lag?

Melatonin, as a sleep aid for jet lack, can help cue the body for rest as it acts like a darkness signal. Melatonin has been known to help people fall asleep during times they normally wouldn’t, according to Health Line in 2019.

What to Expect in Jet Lag Condition?

A person can expect to have trouble sleeping at night and waking up in the morning due to a jet-lagged condition, according to the NHS in 2020. A person can also feel tired, have poor sleep quality, and have trouble staying awake during the day. A jetlag cure to counter this would be to sleep on time in the new time zone using sleeping aides and caffeine during the day to stay awake.

How Long Does Jet Lag Last?

Jet lag lasts 2-3 days to 1-2 weeks, according to the Sleep Foundation in 2023. To understand how long does post travel fatigue last, it’s essential to understand that jet lag affects everyone differently. As a typical rule of thumb, jet lag symptoms increase by 1-1.5 days for each time zone crossed.

How to Get Over Jet Lag?

To learn how to get over jet lag, it’s essential to remember that how long jet lag lasts is the same as how well you prevent it before, during, and after your travels. To know how to get over jet lag, some tips are listed below.


  1. Drink lots of water during your flight. This ensures you stay hydrated and helps your body function better.
  2. Stretch and walk around the plane cabin often to keep your body active and fresh.
  3. If it is the night in your new time zone, it is recommended to sleep on the plane.
  4. To help you sleep, you can use an eye mask, ear plugs, and a pillow.

How long does it take to get over jet lag?

Typically, it takes about a day to recover from every time zone a person crosses during their travels. To understand how to get rid of jet lag, it’s essential to remember that jet lag symptoms are reduced if you are well-rested before your flight. 

Does Sleeping Help in Reducing Jet Lag?

Yes, sleeping before your flight does help reduce a person from feel jet lagged. This keeps your body rested and refreshed for the long journey. Sleeping during your flight is only recommended if it is currently nighttime at your destination. This helps you adjust to the new timezone faster.

Should I keep myself alert to prevent jet lag?

Yes, you should stay awake once you land at your new destination until nighttime. This helps your body adjust to the new time zone faster and helps answer and reduce jet lag lasts how long.

Do you experience Jetlag when traveling from West to East?

Yes, you experience jet lag when traveling from west to east, contributing to feeling like you can t sleep jet lag. This is because you are losing time when traveling to the east, which causes more of a difference in your circadian rhythms.

What is the difference between Jet Lag and travel fatigue?

The difference between travel fatigue vs jetlag is that travel fatigue does not involve sleep pattern changes. Another difference between travel fatigue vs jetlag is that travel fatigue is recovered from much quicker and typically does not need jet lag pills. Jet lag takes longer to recover from. While there is no immediate jet lag cure, treating travel fatigue and jet lag is similar, with rest at the proper times.