August 2020 | Reviewed by: Reeba Mathew, MD and Virginia Skiba, MD
What is jet lag?
Jet lag occurs when you travel across time zones and have trouble adjusting to the new schedule. It is most common after air travel, due to the speed with which time zones are crossed. When you arrive at your destination, your sleep-wake cycle may still be aligned with the previous time zone. Your body may expect to sleep when it is daytime in the new time zone or be awake when you are supposed to sleep.
Jet lag is a temporary condition. It may begin after you travel across at least two time zones. The severity of the jet lag depends on how many time zones you cross and which direction you traveled. Flying east is usually more difficult of an adjustment than westward travel. It is estimated that it takes one day per time zone for your body clock to fully adjust to local time.
You may have a difficult time functioning when you are jet lagged. You may not feel awake and alert when you need to do your job, socialize or sightsee. Anyone of any age can have jet lag, although older adults are likely to have more severe jet lag and may need a much longer time to recover. Some people can adjust more quickly than others to rapid shifts in time zones. Pilots, flight attendants and business travelers are most likely to have jet lag due to their lifestyle.
Jet lag can be worsened by:
- Sleep loss due to travel
- Spending a long time sitting in an uncomfortable position, such as in an airplane
- Stress
- Caffeine and alcohol use
- Air pressure or poor air quality
Jet lag is a circadian rhythm sleep disorder. Your circadian rhythms are your body’s internal clock that signals when you are supposed to feel sleepy or alert. Your body’s clock operates on a roughly 24-hour schedule. It uses sunlight to determine how much of the sleep-promoting hormone melatonin to produce. Melatonin production is high during the evening and very low during the day. As a result, you are alert during the daytime and sleepy at night.
What are symptoms of jet lag?
Jet lag symptoms are likely to be worse and longer lasting the further you have traveled, especially if you travel eastward.
Complaints related to jet lag include:
- Trouble falling asleep
- Feeling tired or disoriented
- Being unable to function normally during the daytime
- Mild sickness
- Stomach problems
- Menstrual symptoms in females
How to diagnose jet lag?
Self test
Have you traveled by air across at least two time zones?
Do you have trouble sleeping or are you very sleepy during the day?
Do you have difficulty functioning normally, a feeling of mild sickness or stomach problems within one or two days after travel?
If you answered yes to each of these questions, then you may have jet lag.
A visit to a sleep doctor is not necessary unless you travel often and continue to struggle, or suspect you have another sleep disorder such as sleep apnea.
You should be able to adjust your sleep schedule and overcome jet lag on your own.
How to treat jet lag?
There are remedies and behavioral adjustments that can help you overcome jet lag after you travel.
Plan ahead
By slowly changing the time that you go to sleep and when you wake up in the weeks before your trip, you should have an easier time adjusting to the jet lag. When the time for the trip comes, your sleep schedule should be relatively close to that of your destination.
Sunlight
Sunlight is a powerful tool to reset your internal clock. After you reach your destination, make sure to open a window or go outside during the daytime to expose yourself to sunlight. This will help you adjust to the new time zone.
Bright light therapy
This involves exposure to a special artificial light at certain times to help reinforce your body clock and ease the transition to a new time zone. This is especially useful if you are frequently indoors or travel to a location without much natural sunlight. Schedule short sessions in the morning and early afternoon with the light. You can use a special light box, desk lamp, visor or dawn simulator for light therapy. However, light exposure on the wrong side of the phase response curve in the new destination can cause a further misalignment. You should talk to your sleep provider before using light therapy.
Melatonin
Melatonin supplements can help your body adjust to jet lag by adjusting your circadian rhythms. Melatonin is a natural hormone produced by the brain’s pineal gland and considered a signal for when your body is supposed to sleep. Research suggests that a dose as low as 0.5 mg is just as effective as higher doses. Since taking melatonin at the wrong time can cause more of a misalignment, talk to your sleep provider before taking melatonin during your travel.
Sleeping pills
Although not recommended routinely, your doctor can prescribe a hypnotic sleeping pill to help you get rest at the proper times when you first reach your destination or to help avoid sleep deprivation during the flight. Sleeping pills may help you sleep better as you adjust to the new time zone. However, they are not necessary and should only be used for a short time. Sleeping medications can cause residual sleepiness after you wake up and can cause abnormal behaviors, such as sleepwalking.
Minimize caffeine and alcohol consumption
Caffeine and alcohol use can interfere with your ability to fall asleep and stay asleep. Use of these substances can lead to dehydration. It is recommended that you avoid these substances while you are travelling across time zones.
Exercise
Some studies have shown that moderate exercise helps adjustment to the new time schedule. Outdoor exercise has the dual advantage of including exposure to sunlight.