All About Jet Lag

Jet lag is a common but short-lived sleep problem you can get after traveling across more than two time zones. Jet lag can make you feel out of sorts due to an abrupt change in your body’s internal clock or circadian sleep rhythms. Symptoms include headaches and difficulty sleeping (insomnia). Learn what you can do to get over or prevent jet lag.

What is jet lag?

Jet lag describes common sleep problems (such as insomnia) and other symptoms people experience after traveling a long distance quickly. When you travel across more than two time zones by plane, your body’s “internal clock” (or circadian rhythm) needs time to adjust to the new sleep and wake cycles at your destination. Jet lag is a type of circadian rhythm sleep disorder.

What are circadian rhythms?

Circadian rhythms are patterns your body follows based on a 24-hour day. These rhythms tell your body when to sleep and when to wake up. They also affect several other body processes, such as hormones, digestion, and body temperature.

Your body sets these rhythms naturally, guided by your brain. But outside factors (such as light) can affect these rhythms, too. For example, when light enters your eye, cells send a message to your brain that it can stop producing melatonin (a hormone that helps you sleep).

How does jet lag happen?

Flying through two or more time zones can upset the circadian rhythms your body knows well. Jet lag means your body is out of sync with the daylight-nighttime schedule of your destination.

Your body will adjust to this change in environment. But it takes time. Think of jet lag symptoms as “growing pains” while your body gets used to your new surroundings.

How common is jet lag?

Jet lag is a common issue many people experience when traveling. However, people can experience jet lag in different ways and to varying degrees. Some people (especially children) may not notice any problems adapting to a new time zone.

Is jet lag worse going east or west?

Medical experts generally agree that flying eastward may cause more severe jet lag symptoms than flying toward the west. Researchers say that’s because your body can adapt more quickly to staying up late than going to bed earlier than normal.

What causes jet lag?

Jet lag usually happens when you travel by plane two or more time zones away. Jet lag symptoms result from your body’s natural rhythms being out of sync with the day- and nighttime hours of your destination.

Plane travel makes jet lag worse because your body moves much faster than your brain and circadian rhythms can process the time change. Other aspects of travel can also contribute to jet lag and may make symptoms worse:

  • Long periods of sitting on a plane.
  • Lack of oxygen and decreased air pressure in the airplane cabin.
  • Warm cabin temperature and low humidity can cause dehydration.

What are the symptoms of jet lag?

You may experience one or more jet lag symptoms:

  • Difficulty falling asleep (insomnia).
  • Drowsiness during the day.
  • Headaches.
  • Lack of focus or concentration.
  • Extreme tiredness (fatigue).
  • A general feeling of being “off” or not like yourself.
  • Upset stomach.
  • Mood changes, such as irritability.