How does jet lag influence passenger and pilot behavior

Jet lag

Frequently asked questions about passenger health

If you need additional advice after reading the guidance on this page please contact your doctor or airline.

Your doctor can contact our Aviation Health Unit for more information.

What is jet lag?

Jet-lag is a problem that is directly related to our ‘body clock’. Almost every function in the body is influenced by a ‘master’ body clock which is located within the brain and sets our ‘circadian rhythms’. These allow our body to predict changes in the environment and help to synchronize sleep and activity over a 24-hour period.

The most important factor in setting our body clock is the cycle of light and darkness. However, our body clock does not cope well with rapid and large changes in the timing of environmental signals like light, which is what happens when we fly quickly across world time zones.

‘Jet-lag’ is the term used for the symptoms you may feel while your body clock adjusts to time in the new location. Symptoms of jet-lag include feeling tired during the day in the new time zone, and yet experiencing disturbed sleep at night, feeling less able to concentrate or to motivate yourself, decreased mental and physical performance, increased incidence of headaches and irritability, loss of appetite and gastro-intestinal problems such as constipation.

How does Jet-lag differ from Travel Fatigue?

Any journey, particularly if more than 3 hours, can cause discomfort and tiredness whether you are travelling by car, bus, train or aeroplane. You may spend long periods in a cramped position and there may be other stresses such as delays, unplanned stops or detours. These symptoms do not last long and often improve after a rest, some light exercise, or a shower or bath. You will usually experience symptoms of travel fatigue after any long-haul flight, but you will only suffer from jet-lag if you cross several (probably more than 3) time zones. You only cross time zones if you travel eastward or westward, so you won’t suffer from jet lag if you fly more or less directly north or south, for example from the UK to Africa or from North to South America.

What affects the severity of jet-lag?

The severity of jet-lag depends on the number of time-zones you cross and, to a lesser extent, on the direction of travel. For most people, the symptoms are worse if they travel eastwards than if they travel westwards. The symptoms may also depend on whether you are a morning-type «lark» or an evening-type «owl». There is little evidence that jet-lag symptoms are different between men and women, or between older and younger people.

Some common sense treatments

The symptoms of jet lag will naturally get better as the body adjusts to the new time zone. However, recovery may take 1-1.5 days per time zone crossed and there are a number of ways in which you can try to speed the process up.

You can start the process of adjustment before you even leave home by changing the time at which you go to bed and get up. If your journey is eastward, for example from the UK to India, you could move your body clock forward by going to bed and getting up an hour earlier. Similarly, if you are travelling westward, for example from the UK to Canada, you could move your body clock backwards by going to bed and getting up an hour later. You should not attempt to re-set your body clock by more than 2 hours before you travel.

If you have a choice of different flight schedules and arrival times, a late afternoon or early evening arrival might be better, since you can «use» the tiredness due to travel fatigue to help you get a full night’s sleep in the new time-zone.

Many travellers find it helpful to set their watches to the time zone at their destination as soon as the flight begins. Depending on the time of your flight, you should try to get some sleep during what would be night-time at your destination. The timing of meals is another cue that helps readjustment of the body clock, but most people have little choice in the timing of meals on the flight. Although the timing of meals can help to synchronise human circadian rhythms, there is little evidence that the content of meals, such as a diet higher in protein or carbohydrate content, speeds up adjustment to the new time zone.

Do any medications help reduce jet-lag?

The most commonly used ‘medication’ is caffeine in the form of caffeinated drinks, such as coffee. Other drinks such as tea or cola usually have lower levels of caffeine and there are also other energising drinks which may have much higher levels. Caffeine will help to combat any daytime sleepiness, allowing you to stay awake until the local night-time. However, it is important that you avoid caffeine in the evening, or you may then find it difficult to get off to sleep when you go to bed.

Sleeping pills help to reduce jet lag symptoms by improving sleep, particularly if you are trying to get to sleep at a time when you would normally be awake and alert at home. Some sleeping pills can also cause daytime sleepiness and should not be taken if you plan to undertake activities such as driving, flying, scuba diving or skiing where this could be dangerous. They should be prescribed by your doctor, not be taken with alcohol and only used for a few days at a time. It is also better not to use sleeping pills during the flight as sleeping in one position in your seat for a long period might increase your risk of deep vein thrombosis (DVT).

Many people find that they fall asleep more quickly after alcohol. Unfortunately alcohol has been shown to reduce the quality of sleep and so this is not a good way of combating the effects of jet lag.

What about melatonin?

Melatonin is produced naturally in the body and is important in regulating our body clock. It is often recommended as an effective treatment for jet lag but in many countries melatonin is not available ‘over the counter’ and has to be prescribed by a doctor. It can also be difficult to be sure of the amount and purity of melatonin bought in health food outlets or on the Internet.

A large number of studies have been undertaken to find out whether melatonin can reduce jet lag symptoms and many have shown that it can be beneficial. However, it is not clear whether these effects are simply due to it acting like a sleeping pill or whether it does help the body clock to adjust to a new time zone more quickly. The effects of melatonin medication are also affected by the body’s natural cycle of melatonin production and it may be important to adjust the time the medication is taken depending on the direction and number of time zones crossed.

In many countries, including the UK, pilots and cabin crew are not allowed to use melatonin when they are on duty (which includes the days off when they are overseas) because of the unpredictability of its effects on alertness.

Does light exposure help to reduce jet-lag?

The most important factor in setting our body clock is the cycle of light and darkness. Not surprisingly, exposure to (or avoidance of) light is an important factor in how quickly you adjust to a new time zone.

Exposure to daylight has the most effect, but the best time to be outdoors if you are trying to combat jet lag depends on your direction of travel and the number of time zones you have crossed.

The table shows recommended times for avoiding or seeking exposure to daylight.

This information is based on an article written by Prof. Greg Atkinson, Health and Social Care Institute, Teesside University: Atkinson, G., et al., From animal cage to aircraft cabin: an overview of evidence translation in jet lag research. European Journal of Applied Physiology, 2014. 114(12): p. 2459-2468

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Jet Lag

Dr Mary Lowth, Reviewed by Dr John Cox | Last edited 17 Sep 2018 | Meets Patient’s editorial guidelines

Jet lag occurs after travelling rapidly across several time zones, because the body’s internal clock has not adjusted to the required sleep-wake cycle in the new time zone.

Jet lag causes physical and psychological symptoms, the severity of which increases with the number of time zones crossed and direction of travel. Eastward travel, when hours are ‘gained’ is associated with worse jet lag than westward travel, when hours are ‘lost.’

Jet Lag

In this article

What causes jet lag?

Jet lag is a group of symptoms caused by disruption to the natural rhythms of the body, called circadian rhythm, by moving quickly across the world’s time zones. It results from a temporary mismatch between the body’s internal clock and the destination sleep/wake schedule.This can either make it hard to fall asleep, or make you sleepy when you’re trying to stay awake. It can also cause dizziness, indigestion, nausea, constipation, altered appetite and mild anxiety.

Before the advent of fast air travel, long journeys were slow enough for us to adjust gradually to different time zones as we travelled. Jet lag occurs when we travel so fast that we ‘gain’ or ‘lose’ extra hours more quickly than our body’s capacity to adjust allows.

You don’t need to travel to get jet lag. Shift work or a series of late nights can have the same effect. This also puts your melatonin and cortisol clocks out of synch with the daylight hours that you need to work to.

If you are travelling over only one or two, or possibly three, time zones, jet lag is not usually a problem. It usually affects people travelling across more than three time zones. So if the time at your destination is more than three hours different to that at the start of your journey, you are likely to experience jet lag. The more the time difference, the greater the problem jet lag is likely to be.

Jet lag only affects people travelling quickly. If you are travelling more slowly, by boat or car, your body clock will be able to adjust gradually.

Book a pharmacy appointment today

Medication for jet lag is available via a prescription from your local pharmacist. Book a consultation to discuss your travel options through the Patient Access app.

What is the circadian rhythm?

We all have an internal clock, managing our body through day and night. Many of the systems in our bodies are affected by it, including appetite and energy levels, and sleepiness. The normal cycle, of sleeping at night and being alert and active in daytime, is called the circadian rhythm.

All living beings, even plants, have an internal clock. The rhythm is a response to the cycle of daylight and darkness.

There are two main components to our internal clock. These are melatonin (produced by a gland in our brain called the pineal gland) and cortisol, (produced by the adrenal gland, on top of the kidney). Both affect arousal (alertness), sleepiness, mood, energy level, and body temperature, and both are mainly regulated by an area of the brain called the hypothalamus, a kind of central control zone located at the base of the brain, behind your eyes.

What is melatonin?

Melatonin is one of the main hormones involved in helping you sleep. Melatonin production occurs mainly when it is dark. Bright artificial light, blue light and natural light, can reduce melatonin levels. Higher melatonin levels are associated with better sleep quality, reduction in depression, and better cognitive performance (this means performance in tasks like attention, reaction time, visual memory and mental maths).

The brain releases melatonin an hour or two before you normally sleep. At the same time body temperature begins to fall, reaching its lowest temperature in the early hours of the morning.

What is cortisol?

An hour or two before expected waking, your body releases cortisol, and then adrenaline (epinephrine). These hormones increase arousal and wakefulness. If levels are high they can make you anxious or uneasy.

Once you have crossed more than three time zones it typically takes the cortisol production pattern one full day to adjust for every time zone crossed. It takes four days to adjust to a four-hour change (even though a two-hour or even a three-hour change can usually be managed without jet lag).

Why does travelling east cause worse jet lag than travelling west?

The principle behind jet lag is that we need a similar amount of quality sleep, in one stretch. It’s not easy to make ourselves sleep for extra hours when we travel, so we mainly need to move the sleep time, increasing or reducing our awake time.

Travelling to the west is easier as the brain finds it easier to move its clock back (by delaying release of melatonin and cortisol and sleeping later), than to move it forward (releasing it earlier).

Travelling to the east is harder, because you have to try to go to sleep when you are not tired, and without your body having produced the melatonin that usually helps this happen.

Who gets jet lag?

People who travel frequently, particularly airline pilots and crew, are most likely to have problems with jet lag. Most people who fly very long distances will be affected, particularly if they fly coach class and can’t easily manage to sleep on the flight even when they are sleepy.

Jet lag can be a problem for athletes competing in different parts of the world, as it is likely to affect physical performance. It is also a concern for business travellers as it may cloud their thinking for several days.

Do some people get worse jet lag than others?

People vary in their ability to adjust to travel across time zones. Whilst people will take on average one day to correct for each hour, once they have crossed more then three time zones, some people take longer than this.

There is a small subgroup of people whose adjustment is very slow to begin, so that their circadian clock does not initially shift. You may know if you are one of these people, as you may experience worse jet lag than others. If this is the case then consider starting the jet lag preparations detailed here 4-5 days prior to travel, rather than only 2-3 days beforehand.

How long does jet lag last?

What are the symptoms of jet lag?

The most common symptoms of jet lag are related to sleep. You may have difficulty getting to sleep at bedtime and struggle to wake up in the morning, or you may be tired long before bedtime and wake up while it is still night and too early to get up.

The effect of this difficulty with sleeping is feeling tired and not being able to function as well as usual. Common symptoms include:

Other aspects of travel, such as cabin pressure, can also have an effect on your digestion. Changes in cabin pressure can cause both lack of fluid in the body (dehydration) and bloating, which may contribute to your symptoms.

How can I avoid jet lag?

It is possible to avoid jet lag but it needs commitment and advance planning. The main key to these strategies it getting enough quality sleep in the few days before your trip, whilst trying to move your sleep period forwards or backwards.

If you try these strategies for 2-3 days before travel (4-5 days if you are a slow adjuster) then you can ‘advance adjust’ your circadian rhythm and reduce or even eliminate jet lag.

How do I reduce jet lag when travelling west?

If you are travelling west then you will gain time, so the principle of preventing jet lag is to prepare in advance by convincing your body it is earlier than it is, whilst continuing to get the right amount of quality sleep.

How do I reduce jet lag when travelling east?

If you are travelling east, then you will lose time, so the principle of preventing jet lag is to convince your body it is later than it is, whilst continuing to get enough quality sleep. You won’t be able to sleep for longer than usual, and your challenge is to move your sleep period backwards and convince your body it is later than it really is. Long-haul flights east from the UK usually dim the lights early to assist you with this.

What should I do to ward off jet lag once I reach my destination?

How do I get over jet lag when I arrive?

The most effective treatments for jet lag rely on shifting the circadian clock to the new time zone as fast as possible.

If you don’t have time to prepare and experience jet lag, it will gradually subside on its own after a few days, as your body clock adapts to the new time zone. There are a number of strategies to help you get over it more quickly:

Ensure good-quality sleep in the darkness

Ensure wakefulness when it’s daylight

Do commercial light devices help with jet lag?

Several online calculators, apps and devices are available to tell the traveller how and when to use the light, when to seek darkness and to seek normal daylight in the days after travelling.

Do jet lag calculators help with jet lag?

Jet lag calculators are online tools that give you an ‘adjustment programme’ to try to prepare for international travel. The idea is that you put your travel details into the calculator and it tells you how to adjust your sleeping patterns prior to, and during, travel.

Many of them are based around the use of light devices, some of which are marketed by the makers of the app or calculator.

Do coloured spectacles help with jet lag?

Do sleeping tablets help with jet lag?

There are no treatments specifically licensed for jet lag. This is partly because adjusting the sleep-wake cycle is complicated, and affected by travel itself. We all adjust differently, and the time at which medicines need to be taken in order to make things better rather than worse, differs between individuals and journeys.

Sleeping tablets are often considered by those trying to get back into a sleeping pattern. However, most doctors will advise against this. Sleeping tablets do not treat jet lag; they only mask it because they don’t reset your circadian rhythm, they just sedate you. They are highly addictive and can affect your ability to fall asleep by yourself even after only a couple of days of use. You also may be more irritable, and perform less well, when you wake.

Does taking melatonin help with jet lag?

Melatonin is often suggested and discussed as a remedy for jet lag. It is not a licensed treatment, although it is a tablet form of the natural melatonin hormone which your brain produces. You might imagine, from reading this leaflet, that melatonin would help jet lag. However, the truth is more complicated.

How do I prevent jet lag in my baby or toddler?

At the best of times, it can be difficult to get your baby or toddler to sleep at the right time, and when you are travelling and everything is strange, worrying, tense or exciting then trying to get them to sleep when you want them to can be an impossible task.

Should I sedate my baby or toddler to avoid jet lag?

Do what your baby does

The preparations above for jet lag only work if you are free to do them. If you are working around a baby or toddler when you are travelling you will need to try to rest when they rest, and accept the need to be awake when they are awake.

You can help yourself by preparing, as much as you can, before you travel, using others to help you get the sleep you need to try to adjust in advance to the new time zone.

How do I manage jet lag in my baby or toddler?

Helping your baby adjust to a new time zone

When you reach your destination and your child is wide awake, give them breakfast. Their jet lag is telling them it is time for breakfast and you won’t be able to convince them otherwise. Accept that you can’t sleep and, if you are tired, just try to be as restful as possible. Read favourite books, give them a warm bath, try not to overstimulate them, but to relax them. Eventually they will need to sleep, but they may hold out longer than you thought possible.

Jet Lag: How Are Pilots And Flight Attendants Affected?

Traveling across the world as a pilot or flight attendant sounds romantic, but their jobs are extremely hard on the body.

Everyday travellers understand that jet lag is part of the travel game.

When people cross just two time zones, the body reacts to the light and time change. From disorientation to stomach nausea, each pilot and flight attendant must fight these sensations to safely transport passengers each day – it’s just one of the challenges when you become a cabin crew member!

What is “Jet Lag”, exactly?

Jet lag isn’t just a sleepy sensation after reaching a destination, but can be a physical reaction to flying and changing time zones.

Some passengers feel nauseated and fatigued. There may be headaches and confusion. Even anxiety could be an issue. Because passengers are traveling for a reason, either business or personal, they could be nervous about a meeting or presentation.

When a pilot or flight attendant feel tired, they must push through the sensation to serve their passengers. Unfortunately, the human body still succumbs to jet lag even if the person continually flies for work purposes.

Why does Jet Lag occur?

World time – it doesnt care for your body clock. Photo credit: Grant.

Some people are affected more than others, and the main reason why it occurs is due to human biological clocks.

Known as circadian rhythms, the human body relies on light and time triggers to indicate active and sleep sections of the day.

A pilot or flight attendant that is crossing the nation will be chasing the sunset when traveling west, effectively making the day seem longer than normal. This prolonged light triggers jet lag symptoms over time.

It’s also thought that cabin pressure adds to the physical ailments. With less oxygen circulating the cabin compared to sea level, a pilot and flight attendant have reduced blood oxygen levels, contributing to jet lag.

Jet Lag cures:

Some amazing myths have surfaced regarding jet lag cures, including a first-class seat purchase. Although passengers may be more comfortable in large, first-class seats, it’s certainly not the answer.

Other travellers have tried to force themselves into a new circadian rhythm using sleeping pills. Essentially, they try to fall asleep with the new time zone.

Some people even believe that alcohol is the magical answer, but none of these tricks truly work.

Coping Strategies of Industry Pros:

The only coping strategies that pilots and flight attendants have are exercise and hydration.

With a little exercise and a lot of bottled water, flight professionals must endure jet lag symptoms with the rest of the passengers. Although they may deal with the symptoms better than amateur travellers, there is no cure for jet lag.

Passengers sleeping in the airport. Photo credit: A. Vaccaro.

5 methods to minimize the effects of Jeg Lag

Passengers feel extremely tired mostly because they’re forced to sit for hours at a time. Here are 5 easy ways to keep jet lag at bay:

There’s no miracle pill to avoid jet lag for anyone flying for an extended period – be it a passenger, flight attendant or pilot. Unfortunatley it’s just the name of the game.

Jet Lag

What Does Jet Lag Mean?

To understand what exactly jet lag means, the meaning of the circadian rhythm of the body needs to be understood. The circadian rhythm is a 24-hour cycle that the body follows naturally. This internal timekeeper regulates your body’s temperature, hormones, and other basic activities.

The hypothalamus, which is the main centre for integrating rhythmic input and developing sleep patterns, is in charge of controlling the circadian cycle. And the interruption of sleep or activity habits, as well as the capacity to be alert and work successfully, is known as jet lag. This is owing to the body’s internal timing mechanisms being out of sync with the external time signals of the final location, particularly the light-dark or day-night cycle and local clock time, as a result of quick travel between time zones. The physical strain of long travels is frequently exacerbated by jetlagging. The misalignment of your body’s internal clock with the local time at your destination is known as jet lag. When travelling across three or more time zones, this behaviour of jet lagging is common. Now with an understanding of what jet lag means, let us explore jetlagging causes, symptoms, jet lag medicine to deal and prevention tips.

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Causes of Jet Lag

When one travels swiftly across two or more time zones, they are more likely to get jet lag. The more time zones one travels across, the more likely they are to feel the symptoms and will probably last longer and be more strong. Jet lag throws off the body’s clock for a variety of reasons.

Dehydration is a common ailment and some symptoms of jet lag may be exacerbated by dehydration. One may become slightly dehydrated if one does not drink enough water during the flight. In addition, humidity levels in planes are low, which might lead to increased water loss.

Jet Lag Symptoms

When your body’s natural rhythms are considerably disrupted by travel, you get jet lag. When you try to force your body’s natural rhythm to meet the new time zone, you may develop jet lag symptoms. These symptoms normally appear within 12 hours of moving into a new environment and can linger for many days. Jet lag causes modest symptoms in the majority of persons. One could be suffering and must be in a physically draining situation if they are having more severe symptoms like cold sweating, vomiting, or a fever. And in such a case one must consult a doctor if these symptoms persist for more than 24 hours. The following are the most prevalent signs and symptoms of jet lag:

Weariness and Exhaustion

A Little Disoriented State of Mind and That Leads to the Perplexity of Thoughts.

Irritable Bowel Syndrome (ibs) and Diarrhoea Are Two Common Gastrointestinal Problems Due to Jet Lag.

A Viral Infection

A Case of Altitude Sickness

Risk Factors Contributing to Jet Lag

There are some risk factors that can cause symptoms to become more severe or linger longer.

Pilots, flight attendants, and frequent business travellers who move between time zones frequently may find it difficult to adjust especially when oscillating between 3 or more different time zones.

Overconsumption of liquor and other alcoholic drinks.

Treatment of Jet Lag

There are multiple jet lag remedies and what may suit one may not suit you so scheduling an appointment with a doctor to get better treatment and heal oneself instead of harming is better. Some ways of treating jet fatigue are as follows:

Therapeutic light- It is one of the most effective jet lag cures. Circadian rhythms can be reset with the use of lighted boxes, lights, and visors. The artificial light imitates sunlight and helps the body wake up. One can use this treatment once they have arrived at their new location to assist one to stay awake during periods of tiredness so the body can adjust.

Sleeping drugs, whether prescription or over-the-counter (OTC), can help one adjust their body clock to the time zone you’re visiting. If possible, one must avoid using them, but if the doctor has recommended sleep medication, one can take it for up to two or three nights if necessary. Avoiding taking it for longer than necessary, is important as these drugs have the potential to become addictive.

Taking time to see the shining sun- The sun’s light signals to your body that it’s time to wake up. When one arrives at their destination if possible one must get outside in the sunlight during prime daylight hours. This can help restore the biological clock and alleviate jet lag symptoms.

Melatonin is a hormone that regulates body clocks and causes jet lag. When the sun sets, the eyes detect darkness and signal the hypothalamus to start generating melatonin, a sleep-promoting hormone. The eyes, on the other hand, inform the hypothalamus to stop producing melatonin when they see sunshine. The hypothalamus, on the other hand, does not modify its timetable quickly; it takes many days. Melatonin is a hormone produced by your body in the hours leading up to bedtime. So when recovering from jet lag and when the body is resisting sleep, one might take over-the-counter (OTC) melatonin pills. Melatonin pills are a fast-acting hormone, so it is recommended to not take them more than 30 minutes before bedtime.

Before travelling, getting enough rest is vital and important to not begin the adventure sleep-deprived.

A light dinner should be eaten a few hours before going to bed.

For a few hours before going to bed, stay away from computer, TV, and phone screens.

A few hours before bedtime, dim the lights.

To help sleep better, trying chamomile tea or lavender essential oils has proven to be effective.

Consume food at regular intervals- To assist your body in following the new cues, eat at the proper time for your new time zone. When you do go to bed, the meals you eat can have an impact on the quality of your sleep.

Prevention Tips for Jet Lag Fatigue

If you’re flying into a city where it’s nighttime, try to stay up for a few hours before landing. This is when using screen time and light to help rewire your sleep routine is a wonderful idea. To adjust to the new time zone, go to bed when you arrive and wake up in the morning.

Conclusion

If you fly a lot and have trouble with jet lag, contact a sleep specialist, who is a physician or psychologist who specialises in sleep medicine. Sleep specialists can help you shift your body’s circadian rhythm toward your new time zone in a variety of ways, such as using light therapy, melatonin, or prescription medicine that can aid with jet lag symptoms. Your body may take several days to acclimate to the new time zone. Making immediate changes to your eating, working, and sleeping patterns can help speed up the process. You may have signs of jet lag as you acclimate. Jet lag will most likely dissipate within a few days after your arrival. Allow yourself enough time to acclimatise to your new schedule, and you’ll still be able to enjoy your vacation.

What is Jet Lag? Symptoms, Risk Factors & How to Get Over

It could mean even more to your body, and if you don’t know what it is, here we’re going to give you some jet lag tips on what it really is and how to get rid of it.

What is Jet Lag?

The first thing to know about Jet lag is that it’s an effect of air travel through a number of time zones in the circadian rhythm of our body. Circa is the Latin word for “about” and diem means “day.” This rhythm has a clock of approximately 24 hours.

The body operates with many circadian rhythms, such as body temperature regulation, hormone function, airway function, and kidney function. When we’re in a place, our body becomes accustomed and engages all its rhythm to that internal clock.

When we travel through multiple time zones, the time zone changes but our body clock is still in the time of the region we left, that means that our body is not in sync with the area where we are. That’s a very important factor to consider.

It doesn’t matter if it’s a trip with your family, business travel or any other reason. Planning and taking it into consideration is the best way to face it. Don’t let your trip be ruined by not taking the necessary precautions.