A Health Expert Explains the Science Behind Jet Lag — and How to Combat It

When it comes to international travel, the jet lag is so real. When it strikes, it's not something a strong cup of coffee or afternoon catnap can fix. The fatigue you experience is actually a temporary sleep disorder caused by traveling quickly across multiple time zones. We spoke with Dr. Teofilo Lee-Chiong, MD, chief medical liaison for Philips Respironics, to explain the science behind the phenomenon.

"Jet lag normally occurs within one to two days following rapid air travel across multiple time zones. As your body attempts to synchronize to your new local time zone, you will experience a variety of symptoms based on your direction of travel. Eastward and westward air travel plays a significant role in how you experience jet lag as eastward travel leads to a phase-delayed circadian period (shifting to a later time in the 24-hour cycle) and difficulty waking up the next day. Westward travel results to a phase-advanced circadian period (shifting to an earlier time in the 24-hour cycle) with early evening sleepiness and an early wake-up time."

So to your body, it does make a difference whether you're traveling into the future or backtracking into earlier time zones. Other symptoms can sneak up on you regardless of which direction you're flying. They include decreased alertness, reduced concentration, fatigue, lightheadedness, etc. On average, the symptoms persist for about one day per every time zone traveled.

But are we all doomed to spend the first few (or more) days of our vacation walking around like zombies? According to Dr. Lee-Chiong, the best way to combat the pesky phenomenon is getting some restful shut-eye when you're traveling to the destination. He recommends controlling any distractions with things like noise-canceling headphones and heavy-duty earplugs, not getting lost in the media screen, avoiding heavy foods and alcohol, wearing comfortable travel clothes, and meditating to relax your mind.

And if the symptoms still follow you home? "Consider taking a dose of melatonin supplements to help your body jump-start the natural production of this hormone — your sleep and wake cycles will quickly shift back to normal."