Jet Lag: Symptoms, Risk Factors, and More

Last updated: April 1, 2019

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If you’ve traveled to another country or continent and found yourself feeling irritable and unable to sleep, you may have jet lag. It can also cause a person to have unexplained headaches. Jet lag is also known as time zone change syndrome or desynchronosis.

This is a physiological condition that a person experiences when that person’s Circadian Rhythm gets disrupted. For this reason, jet lag is considered as a Circadian Rhythm Disorder.

What exactly is jet lag?

Jet lag happens when the sleep-wake cycle of a person gets disturbed. As a result, that person becomes drowsy and lethargic. He may also feel irritable, tired, and slightly disoriented.

Jet lag is often experienced by those who travel across multiple time zones in a short period of time. The more time zones a person crosses, the more severe the jet lag is. However, it is not only those who cross time zones who are prone to jet lag. People who frequently change their sleep routine because of work commitments can also experience jet lag.

What causes jet lag?

As mentioned above, jet lag results from the disruption of the body’s Circadian Rhythm. This is why it is important to learn more about Circadian Rhythms and what they do for the human body.

What are Circadian Rhythms?

The Circadian Rhythm is the 24-hour internal clock that runs in the background of the brain. This clock cycles between feelings of alertness and sleepiness throughout the day. It has regular intervals that it follows and is also called the sleep-wake cycle. This cycle is the reason why a person will feel alert or energized at about the same time each day. There will also be particular times when the human body will feel sleepy or tired.

A part of the brain called the hypothalamus controls the Circadian Rhythm. However, other factors such as lightness and darkness can also affect the sleep-wake cycle. When the surroundings are dark, the eyes send a signal to the hypothalamus that it is time to sleep. The brain then sends a signal to the body to produce melatonin which makes the body feel tired and sleepy. On the other hand, when the human body senses light, the brain receives a signal that it is time for the body to become alert so a person wakes up. This is why the Circadian Rhythm follows the daytime and nighttime cycle. This is also one reason why those who work the graveyard shift have trouble sleeping during the day and staying active during the night.

What is the relationship between time zones and my body clock?

We already know what the body clock is. For us to completely understand the relationship between time zones and the Circadian Rhythm, we need to know what a time zone is.

A time zone is a region which has the same time. There are 24 time zones around the world. We have one time zone for each hour of the day. Time zones run from north to south and they are approximately 1,000 miles wide. Each time zone is one hour ahead from the time zone before it and one hour behind from the time zone ahead of it. When the earth rotates, you have one time zone where the sun is setting. An hour later, the sun will set on the time zone west of the previous one. This goes on and on until the 24-hour cycle is complete. So, here in the U.S., if it’s 8 PM in the Eastern Time Zone, it is 7 PM in the Central Time Zone, 6 PM in Mountain Time, and 5 PM in Pacific Time.

A person experiences jet lag because the body of the traveler cannot immediately adjust to the time in another time zone. If you live in San Francisco and you want to take a vacation in Australia, you need to cross multiple time zones. When you land in Sydney, your body is still operating in Chicago time. This means that your body needs to adjust to a new schedule. This forced and immediate adjustment can cause temporary insomnia, fatigue, lack of focus and irritability. Your brain may get confused and disoriented as it attempts to cope with the new schedule.

It is important to remember that a person only experiences jet lag if he quickly crosses multiple time zones. Crossing just one time zone won’t have too much effect on the body clock. So does crossing multiple time zones slowly. If you drive across the continental United States and you stay in one time zone for a day or two before moving to the next time zone, you won’t experience jet lag. Your body will have enough time to adjust to the new time zone.

Traveling from West to East

Jet lag also happens only to those who travel from east to west or west to east. Between the two, traveling from west to east can cause more severe symptoms of jet lag. When a person travels from east to west, he adds hours to his day. The day gets shorter but the sleeping time of the body remains the same. On the other hand, when a person travels from west to east, that person is reducing the hours in his day. Fewer hours of the day means the body has less time to adjust to the changes to the schedule. There is also less time for the body to sync with the new Circadian Rhythm.

When a person travels from north to south or south to north, the chances of getting jet lag gets reduced. This is because that person doesn’t cross time zones, as long as he travels in a straight line. If you’re from Chicago and fly directly to Belize for a vacation, you’re not crossing any time zones. You might experience some discomfort because of the sudden change in the season but you won’t experience jet lag.

What other factors affect jet lag?

According to the World Health Organization (WHO), consuming alcohol or caffeine before or during a flight may worsen the symptoms of jet lag. The consumption of alcohol and caffeine can add to dehydration. Drinking alcohol increases a person’s need to urinate and this can disrupt sleep. Although alcohol is known to induce sleep, alcohol-induced sleep has a lower quality compared to natural sleep. The hangover that alcohol causes can also worsen the effects of jet lag.

Caffeine, on the other hand, is known to disrupt sleep patterns.

Altitude Sickness

The pressure in the cabin of an airplane is lower than the pressure at sea level. It means that when flying, a person’s brain gets less oxygen. This can cause lethargy. The reduced amount of oxygen can worsen jet lag symptoms. Changes in air pressure can also lead to lower levels of oxygen saturation. When a person spends at least 3 hours in a place where there is a low level of oxygen saturation, he will feel discomfort and experience symptoms that resemble those of altitude sickness.

What are the symptoms of jet lag?

The symptoms of jet lag can vary. Older people can experience symptoms that are more severe compared to younger ones. The older the person is, the more difficult it is for his body to adjust to time differences. It also takes an older person longer to recover from the symptoms of jet lag.

The number of time zones crossed also dictate the symptoms and their severity. When a person crosses more time zones, the symptoms of jet lag can be more severe because there will be a huge time difference between the location where his body clock is in sync and his destination.

The most common symptoms of jet lag are:

  • Disturbed sleep
  • Insomnia
  • Daytime fatigue
  • Stress
  • Headaches
  • Irritability
  • Lack of concentration
  • Indigestion and irregular bowel movements

How can I treat jet lag?

As of the moment, there is no treatment for jet lag. However, if you are a frequent traveler, there are ways that can help you minimize jet lag symptoms. You can start by ensuring that you are physically fit and healthy. A physically fit person has fewer and less severe symptoms compared to someone who is not as fit. You can start by always getting enough rest. You can also maintain a well-balanced diet.

Some medical conditions can also make jet lag symptoms worse. If you have lung disease, diabetes, or heart disease, the symptoms that you might experience are more severe. If you have such ailments but need to embark on a long trip, seek your doctor’s advice so you can get help in preparing for such a trip.

Prescription sleep medication can help reset your body clock to that of your destination. This is not a cure but a way of helping your body clock adjust faster. You can take melatonin receptor agonists like ramelteon or sedative-hypnotics like zolpidem or zaleplon.

Here are some tips on how you can prevent or minimize the effects of jet lag:

Adjust your body clock in advance.

Let’s say that you’re going to a place that’s 5 hours ahead of your local time, you can try to adapt to the sleep patterns of your destination in advance. A few days before you travel, begin going to sleep 30 minutes to 1 hour earlier than your regular schedule. Adjust it again the following day and so on until your bedtime is as close as possible to the bedtime in your destination.

If you are traveling somewhere that’s 5 hours behind your local time, you need to do the opposite of what’s above. Stay a bit later each night until you’re going to bed about the same time as the bedtime of your destination.

Keep yourself active during the flight

If you’re on a long flight, you need to keep yourself active. Do not spend the entire flight sitting or sleeping in your seat. Perform some exercises and stretching. You can also walk along the aisle from time to time to ensure blood circulation in your legs. Spending the entire flight on your seat will weaken your body and you’ll feel tired upon reaching your destination.

Arrive early

If you’re traveling because of work or business matters, choose a flight that gets you earlier to your destination. This will give more time for your body to adjust to the new time zone. This way, you can be sure that by the time that you need to be alert and sharp for business matters, you have already adjusted and you no longer feel the symptoms of jet lag.

Light Therapy

Upon arrival on your destination, spend some time outdoors. This is crucial especially if you arrive on your destination while there’s still light outside. Getting sunlight on your face and eyes can help you adjust faster to the new time zone that you’re in.

Melatonin Supplements

Melatonin is a hormone that our bodies need to help us fall asleep. Taking 3 milligrams of melatonin supplement approximately 3 hours before bedtime can aid in falling asleep. It is important to note though that there is no conclusive evidence that melatonin supplements are effective in relieving the symptoms of jet lag. You need to seek your doctor’s professional opinion if you intend to take melatonin supplements as a jet lag treatment.

Jet lag is something that we will experience whenever we travel to a place that’s several time zones away. This is due to our body’s need to adjust itself to the sleep-wake cycle that’s completely different to what it’s used to.

There is no treatment for jet lag. That is not to say that we should just steel ourselves for it whenever we travel. There are precautions and preparations that we can do to minimize, if not completely eliminate the symptoms of jet lag.

Being prepared before a journey can help us make sure that our vacation won’t get ruined by jet lag. It can also help us make sure that we are at our best if we are traveling for business. When we are prepared, the effects of jet lag will be so minimal that it’s as if we hardly have any jet lag at all.

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