Everything you need to know about jet lag.
By Jill Case
What is jet lag? The medical name for jet lag is desynchronosis, or time zone change syndrome. The condition occurs during air travel from east to west or west to east, when people fly from one time zone to another. Jet lag is a real physiological condition (so, no, it’s not your imagination when everything feels off) that is classified as a circadian rhythm disorder. Circadian rhythms serve as the body’s biological clock, controlling the physiological, biochemical and behavioral processes that govern our body. Therefore, when they are disrupted, everything from when we sleep and wake, to eat are disturbed.
Symptoms of Jet Lag
The symptoms of jet lag vary depending on your age, your health, the number of time zones you have crossed, how much sleep you had before and during the trip, how much you had to eat and how much alcohol you drank during the flight. Some people are simply more susceptible to jet lag than others and will experience more symptoms with more severity than others do. Symptoms may include:
- mood changes (irritability, mild depression)
- difficulty concentrating
- confusion, or even some memory loss
- loss of appetite
- sweating or problems controlling body temperature
- diarrhea or constipation
Ways to Prevent Jet Lag
There is nothing that works for every person, but here are some tips for travelers who have some time to prepare before the trip:
- Begin going to bed and getting up on the new timezone schedule a few days before your trip. Adjust your meals as well.
- If you are taking a long trip, consider breaking it up into two shorter routes with a stop in the middle to rest and regroup.
- Try to arrive a few days early to allow your body to adjust before you have any important meetings.
- Eat healthy and get adequate rest before your trip.
Tips for every traveler
- As soon as you get to the airport, set your watch to the new time zone.
- When you get on the plane, if you are able (don’t stress about it), try to sleep if you would normally be sleeping in the new time zone or stay awake if it is morning at your destination.
- Bring earplugs and/or an eyemask so that you are able to sleep better during the flight.
- Drink water to stay hydrated.
- Avoid caffeine and alcohol as much as possible during the flight.
- If possible, try to get up and walk around, or at least move your legs during the flight to improve your circulation.
- Eat healthy foods, but don’t eat heavy meals.
- Be certain to keep taking your medications and following all medical treatment plans for any existing health condition you may have.
- If you have experienced severe jet lag in the past, talk to your doctor to see if he or she thinks sleep medications may help you.
- If you are a frequent traveler and you have a serious problem with jet lag, consider talking to a sleep specialist about your problem and how it may be treated.
Ways to Cope with Jet Lag on Arrival
- If you haven’t already done so on the flight, immediately adjust your routines (sleeping, eating) to the local time zone.
- Continue to drink water to stay hydrated, and try to avoid excessive amounts of caffeine or alcohol until you adjust.
- Do not go to sleep if it is not bedtime locally. Instead, take a short 20- to 30-minute nap or two until it is time for bed at your destination.
- Get outside and enjoy some daylight. Some research suggests that exposure to light (from the sun or a special lamp) at the appropriate time of day can help reset your body clock.
Frequently Asked Questions
Melatonin—Does it Help?
Many people know that melatonin is a supplement that they can buy, but many do not realize that the body produces its own melatonin. It’s a hormone produced by the pineal gland in the brain that controls your circadian rhythms. Normally, your body’s melatonin levels rise and fall with your body clock, rising during the evening to its highest point at night and then falling during the early morning. When your circadian rhythms are disrupted by travel across time zones, your body’s production of melatonin is also disturbed. Studies have shown that taking melatonin supplements may help with jet lag, and they are available over the counter, but you should always talk to your doctor about potential interactions with other medications or problems with your medical conditions before taking any over-the-counter supplements. It is recommended that you take between 3 to 5 milligrams an hour or two before bedtime at your destination. You may continue to do this for a few days to help regulate your body clock. Melatonin appears to be most effective for long trips in which you cross five or more time zones, but it is also effective for many people who are crossing fewer than five time zones.
How long does jet lag typically last?
Jet lag usually does not occur until you have crossed three or more time zones. One theory is that it takes your body one day to adjust to every one to two time zones crossed (after the first three). This means if you crossed five time zones, it may take the average person one to two days to adjust.
Is jet lag worse when you go from east to west or west to east?
It’s worse when you travel from the west to the east because you lose time. For example, if you fly from Austin to London, you lose six hours (if it’s 12 p.m. CST in Austin, it is 6 p.m. in London). This time loss throws off your eating and sleeping routines. Conversely, when you travel from east to west, you gain time (again, traveling from London to Austin, you would gain six hours), making the adjustment a bit easier, although you would still experience jet lag symptoms, but they would probably be less severe.
What happens when you travel from north to south or south to north?
When traveling north to south, jet lag is usually not an issue because there is not a big difference in time zones. For example, if you travel from Austin to Chile, there will only be a one-hour time difference because Chile is in the Eastern Standard time zone. You may, however, still experience symptoms like fatigue and other signs of jet lag simply due to the rigors of a long trip. To find the time zone for your destination, go to worldtimeserver.com/convert_time_ in_US-TX.aspx.