Jet lag what is it

Jet lag occurs because your body's clock is still synced to your original time zone, instead of to the time zone where you've traveled.

The more time zones crossed, the more likely you are to experience jet lag. Jet lag can cause daytime fatigue, an unwell feeling, difficulty staying alert and gastrointestinal problems. Jet lag is temporary, but it can significantly reduce your vacation or business travel comfort. Fortunately, there are steps you can take to help prevent or minimize jet lag.

Symptoms of jet lag can vary. You may experience only one symptom or you may have many. Jet lag symptoms may include:. Jet lag symptoms usually occur within a day or two of travel if you've traveled across at least two time zones. Symptoms are likely to be worse or last longer the more time zones that you've crossed, especially if you travel in an easterly direction.

It usually takes about a day to recover for each time zone crossed. Jet lag is temporary. But if you're a frequent traveler and continually struggle with jet lag, you may benefit from seeing a sleep specialist. Jet lag can occur anytime you cross two or more time zones. Jet lag occurs because crossing multiple time zones puts your internal clock circadian rhythms , which regulates your sleep-wake cycle, out of sync with the time in your new locale.

For example, if you leave New York on a flight at 4 p. Wednesday, your internal clock still thinks it's 1 a. That means you're ready for bed just as Parisians are waking up. And because it takes a few days for your body to adjust, your sleep-wake cycle, along with most other body functions, such as hunger and bowel habits, remains out of step with the rest of Paris.

A key influence on your internal clock is sunlight. That's because light influences the regulation of melatonin, a hormone that helps synchronize cells throughout the body. Certain cells in the tissue at the back of your eye retina transmit the light signals to an area of your brain called the hypothalamus. At night, when the light signal is low, the hypothalamus tells the pineal gland, a small organ situated in the brain, to release melatonin. During daylight hours, the opposite occurs, and the pineal gland releases very little melatonin.

These neurons are part of a structure called the suprachiasmatic nucleus SCN , located in the anterior portion of the hypothalamus at the base of the brain. Scientists say the SCN adjusts slowly to changes in time zone while other body clocks, or neuron groups, adapt at different rates.

One of these groups of neurons has links to deep sleep and the effects of physical fatigue. Another group controls the dream state of rapid eye movement REM sleep. The group involved in REM sleep finds it harder to adjust to the new cycle, and the two groups, or clocks, get out of sync. An internal time-keeping system drives the body clock. Changes in the light-dark cycle of night and day signal to the body that it needs to adjust. Changes in mealtimes, exercise, and other routines, can also contribute.

Situations that can cause the body clock to get out of sync include :. Jet lag will continue to disrupt sleeping, waking, eating, and other routines until the body clock recalibrates to suit the new environment.

When traveling eastward, symptoms can feel more severe because the body has less time to recover. Traveling westward adds hours to a day, but traveling eastward reduces them.

As a result, a person has less chance to catch up with sleep, which can delay recovery. One study of 10 athletes found that jet lag continued to impact athletic performance up to 4 days after traveling across eight time zones from west to east. In contrast, their performance significantly recovered by day 2 after traveling the opposite way.

When traveling between north and south, changes in season may affect a person. However, for jet lag to occur, there must be an east-west or west-east movement. For example, flying directly south from Chicago to Santiago in Chile may cause discomfort, but it will not lead to jet lag.

The World Health Organization WHO recommends limiting the consumption of alcohol or caffeine during or before flights, as they may worsen symptoms of jet lag. They may exacerbate them by contributing to dehydration and affecting sleep quality. A study in mice found a possible link between environmental levels of oxygen and jet lag. This could result in lethargy, which may worsen the symptoms of jet lag.

The researchers suggested that oxygen modulation therapy could help reduce the effects of jet lag. There is currently no treatment for jet lag and no medical approach that can cause the body clock to reset. However, researchers have looked at several options. They include controlling light exposure , possibly with one or more of the following:. Caffeine and alcohol use can interfere with your ability to fall asleep and stay asleep.

Use of these substances can lead to dehydration. It is recommended that you avoid these substances while you are travelling across time zones. Some studies have shown that moderate exercise helps adjustment to the new time schedule. Outdoor exercise has the dual advantage of including exposure to sunlight.

Jet Lag. Jet lag can be worsened by: Sleep loss due to travel Spending a long time sitting in an uncomfortable position, such as in an airplane Stress Caffeine and alcohol use Air pressure or poor air quality Jet lag is a circadian rhythm sleep disorder. What are symptoms of jet lag? Complaints related to jet lag include: Trouble falling asleep Feeling tired or disoriented Being unable to function normally during the daytime Mild sickness Stomach problems Menstrual symptoms in females.

How to diagnose jet lag? Self test Have you traveled by air across at least two time zones? Do you have trouble sleeping or are you very sleepy during the day?

If you answered yes to each of these questions, then you may have jet lag. You should be able to adjust your sleep schedule and overcome jet lag on your own.

How to treat jet lag? Plan ahead By slowly changing the time that you go to sleep and when you wake up in the weeks before your trip, you should have an easier time adjusting to the jet lag.

Sunlight Sunlight is a powerful tool to reset your internal clock. Bright light therapy This involves exposure to a special artificial light at certain times to help reinforce your body clock and ease the transition to a new time zone. Melatonin Melatonin supplements can help your body adjust to jet lag by adjusting your circadian rhythms.

Sleeping pills Although not recommended routinely, your doctor can prescribe a hypnotic sleeping pill to help you get rest at the proper times when you first reach your destination or to help avoid sleep deprivation during the flight. Minimize caffeine and alcohol consumption Caffeine and alcohol use can interfere with your ability to fall asleep and stay asleep.