What is jet lag?

Jet lag is a fatigued, out-of-sync feeling you experience after flying across several time zones. The rapid travel disturbs your normal body rhythms.

How does it occur?

Each person has an internal body clock that determines when sleeping, waking, and hunger occur in a 24-hour period. When you travel across several time zones, your day is longer or shorter than 24 hours. Your normal body rhythms cannot adjust quickly to this shorter or longer day, which results in jet lag.

Not all jet lags are the same. Traveling eastward, which shortens your day, is more difficult than flying westward, which lengthens it.

What are the symptoms?

The symptoms of jet lag may include:

• fatigue

• drowsiness during the day

• difficulty in sleeping

• dulling of mental ability and memory

• irritability

• headaches

• gastrointestinal discomfort, diarrhea, or constipation

• minor coordination problems and reduced physical activity.

How long will the effects of jet lag last?

West-to-east trips require one day of recovery for each time zone crossed; east-to-west journeys require one day for each one and a half time zones crossed.

The adjustment can be eased by breaking up a long journey with a stopover. If you have an important event or meeting to attend at your destination, try to get there two or three days early.

What can be done to help prevent jet lag?

The following can help minimize the symptoms of jet lag:

• Drink lots of beverages during the flight, but avoid those containing caffeine or alcohol.

• Eat high-protein, low-calorie meals just before, during, and just after your flight.

• If you fly east, you should go to bed earlier than usual for a few days before the trip; if you fly west, you should go to bed later than usual.

• Schedule your arrival at about your usual bedtime, according to the time at your destination, or sleep on the plane and plan to arrive at your usual waking time.

• Set your watch to the destination time when you are halfway through your flight, so you can start thinking in terms of the new time.

• Spend more time outside at your destination. This exposure to bright outdoor light will help you to adjust faster than if you stay in your hotel room.

How do I adjust medications prescribed at a certain hour?

If you are diabetic and use long-acting insulin, you may have to change to regular insulin until you have adjusted to the time, food, and activity of your destination.

You may have to adjust other medication schedules according to the actual hours between doses rather than the local time at your destination.