Jet lag, or jet lag disorder, is a temporary sleep disorder that can be experienced by anyone traveling across different time zones. This is typically by way of high-speed travel, such as an airplane or high-speed train.  Jet lag can cause daytime fatigue and tiredness, difficulty staying awake or alert, and even gastrointestinal problems. Jet lag is a temporary sleep disorder, but it can cause complications with your comfort and ability to function when traveling to different places for work or vacation. 

Circadian Rhythm Disruption

Your body has its own internal clock, called the circadian rhythm. This circadian rhythm sends signals to your body when it is time wake up or when it is time to go to sleep. When you travel, your circadian rhythm stays synced to the time zone at home. This means that jet lag occurs because your body is out of sync with the time zone to which you have traveled. Generally, the more time zones you cross and the faster you cross them, the worse your jet lag will be.

Jet lag occurs whenever you cross multiple time zones because your circadian rhythm is out of sync with the time zone at your destination. For example, if you leave San Francisco at 1 p.m. on Monday and arrive in New York City at 9:30 p.m., you might by hungry for dinner while many New Yorkers are getting ready for bed. This is because your body still thinks it is about 6 p.m. As you can see from the example, a number of bodily functions, such as sleep, hunger, and bowel movements can be out of sync with your travel destination. Jet lag is simply a heightened level of discomfort and fatigue caused when your circadian rhythm adjusts to a new time zone.

Influence of Sunlight

Sunlight is a key factor in your body’s ability to maintain a circadian rhythm. Sunlight influences the regulation of melatonin, which is a hormone that helps regulate your body’s sleep cycle. Melatonin is produced by the pineal gland whenever your body detects low light levels. That means that during daylight, the pineal gland produces only small amounts of melatonin.

To put this into the context of jet lag, that means if you arrive in a location during the day, but it is dark at home, your circadian rhythm would expect the pineal gland to start releasing melatonin even though it is daylight. Still, it may be possible to make your adjustment to a new time zone smoother by spending time outside during midday daylight hours, even if you feel tired.

Prevention and Treatment

There are a few steps you can try to avoid jet lag or limit its impact on you.

• Adjust your schedule prior to travel. Depending on which direction you are planning to travel, you can try changing your sleep schedule by an hour, several nights before leaving. For eastward travel, go to bed an hour earlier. If you are planning to travel west, then you would stay up an hour later.
• Get plenty of sleep before traveling. Starting out sleep-deprived makes jet lag worse.
• Sleep on the plane. Althoughsleeping on the plane can be difficult sometimes, it is one of the most popular suggestions for preventing or reducing jet lag. If it is night at your travel destination while you are on the flight, sleeping can help a lot by giving you a head start on adjusting to the new schedule.
• Arrive early. Arriving a few days early gives your body time to adjust. This does not reduce symptoms but gives you time to cope with jet lag before doing any activities.
• Spend time in sunlight or bright light. Since daylight and light are key factors in your body’s circadian rhythm, scheduling some time in daylight can help you adjust to your new schedule. There is an exception to this suggestion if you have traveled across more than eight time zones. Your body can confuse dawn and dusk, so it may best to avoid being outside during dawn or dusk until your body better adjusts to your travel destination.
• Drink plenty of fluids. Dehydration makes jet lag symptoms worse, so drink plenty of water and avoid alcohol and caffeine.
• Stay on your new schedule. When traveling, try to stick to the schedule of your travel destination. For example, avoid sleeping until nighttime, even if you are exhausted. You can also eat your meals at local mealtimes too.

Jet lag is an uncomfortable experience when traveling. It can make someone feel completely thrown off for a few days until they adjust to a new schedule. Fortunately, there are a lot of different things you can do to prevent or limit the effects of jet lag. The key is planning ahead before you