Jet lag, medically referred to as desynchronosis and rarely as circadian dysrhythmia, is a temporary sleep disorder that can affect anyone who quickly travels across multiple time zones. Jet lag can occur when people travel rapidly from east to west, or west to east on a jet plane. It is a physiological condition which upsets our body’s circadian rhythms – hence, it is classified as a circadian rhythm disorder. Jet lag is a temporary sleep disorder, but not temporary enough for many travelers. If you’re flying from San Francisco to Rome for a 10-day trip, for example, it may take six to nine days to fully recover. That’s because it can take up to a day for each time zone crossed for your body to adjust to the local time. If you’re traveling east to west, from Rome to San Francisco, jet lag could last four to five days, about half the number of time zones crossed. Jet lag is generally worse when you “lose time” traveling west to east.
If you’re an older adult, jet lag may hit you harder and recovery may take longer.
A disruption to your circadian rhythms
Jet lag can occur anytime you cross two or more time zones. Jet lag occurs because crossing multiple time zones puts your internal clock or circadian rhythms, which regulate your sleep-wake cycle, out of sync with the time in your new locale.
For example, you lose six hours on a usual New York to Paris flight. That means that if you leave New York at 4:00 p.m. on Tuesday, you arrive in Paris at 7:00 a.m. Wednesday. According to your internal clock, it’s 1:00 a.m., and 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.
Airline cabin pressure and atmosphere
Some research shows that changes in cabin pressure and high altitudes associated with air travel may contribute to some symptoms of jet lag, regardless of travel across time zones.
Not drinking enough water during your flight can dehydrate you. In addition, drinking too many beverages with caffeine or alcohol during your flight can affect your sleep and cause some symptoms of jet lag.
The influence of sunlight
A key influence on your internal clock is sunlight. That’s because light influences the regulation of melatonin, which in turn is a synchronizing signal to cells throughout the body.
Certain cells in the tissue at the back of your eye (retina) transmit the signal of light to an area of your brain called the hypothalamus. At night, when this signal is low, the hypothalamus tells the pineal gland, a small organ situated in the brain, to release the hormone melatonin. During the day, the light signals to the hypothalamus result in the opposite, such that the pineal gland produces very little melatonin.
You may be able to ease your adjustment to your new time zone by exposing yourself to daylight in the new time zone so long as the timing of light is done properly.
A symptom is something the patient senses and describes, while a sign is something other people, such as the doctor notice. For example, drowsiness may be a symptom while dilated pupils may be a sign. Symptoms of jet lag vary and depend on several factors, including how many time zones were travelled, the individual’s age, state of health, whether or not alcohol was consumed during the flight, how much was eaten during the flight, and how much sleep there was during the flight.
The following are typical jet lag symptoms:
- Head feels heavy
- Lethargy, fatigue
- Mild depression
- Attention deficit – hard to concentrate on one thing for long
- Loss of appetite
- Slight confusion
- Dizzy unsettled feeling – this may be due to moving from the plane, which wobbles all the time, to firm land.
- Some gastrointestinal disturbances, such as diarrhea or constipation.
Jet lag usually doesn’t require treatment. However, if you’re a frequent traveler continually bothered by jet lag, your doctor may prescribe medications or light therapy.
- Nonbenzodiazepines, such as zolpidem (Ambien), eszopiclone (Lunesta) and zaleplon (Sonata)
- Benzodiazepines, such as triazolam (Halcion)
These medications may help you sleep during your flight and for several nights afterward. Side effects are uncommon, but may include nausea, vomiting, amnesia, sleepwalking, confusion and morning sleepiness. Although these medications appear to help sleep duration and quality, they may not lessen daytime symptoms of jet lag.
Your body’s internal clock or circadian rhythms are influenced by exposure to sunlight, among other factors. When you travel across time zones, your body must adjust to a new daylight schedule and reset, allowing you to fall asleep and be awake at the appropriate times.
Light therapy can help ease that transition. It involves exposing your eyes to an artificial bright light or lamp that simulates sunlight for a specific and regular amount of time during the time when you’re meant to be awake.
This may be useful, for example, if you’re a business traveler and are often away from natural sunlight during the day in a new time zone. Light therapy comes in a variety of forms including a light box that sits on a table, a desk lamp that may blend in better in an office setting or a light visor that you wear on your head.
Coping with Jet Lag
There are several home remedies that can help with prevention of jet lag and easier recovery from the symptoms. The following are 12 tips to help travelers to avoid or to minimize the effects of jet lag.
Tip 1: Stay in shape
If you are in good physical condition, stay that way. In other words, long before you embark, continue to exercise, eat right, and get plenty of rest. Your physical stamina and conditioning will enable you to cope better after you land. If you are not physically fit, or have a poor diet, begin shaping up and eating right several weeks before your trip.
Tip 2: Get medical advice
If you have a medical condition that requires monitoring (such as diabetes or heart disease), consult your physician well in advance of your departure to plan a coping strategy that includes medication schedules and doctor’s appointments, if necessary, in the destination time zone.
Tip 3: Change your schedule
If your stay in the destination time zone will last more than a few days, begin adjusting your body to the new time zone before you leave. For example, if you are traveling from the U.S. to Europe for a one-month vacation, set your daily routine back an hour or more three to four weeks before departure. Then, set it back another hour the following week and the week after that. Easing into the new schedule gradually in familiar surroundings will save your body the shock of adjusting all at once.
If you are traveling east, try going to sleep earlier and getting up and out into the early morning sun. If traveling west, try to get at least an hour’s worth of sunlight as soon as possible after reaching your destination.
Tip 4: Avoid alcohol
Do not drink alcoholic beverages the day before your flight, during your flight, or the day after your flight. These beverages can cause dehydration, disrupt sleeping schedules, and trigger nausea and general discomfort.
Tip 5: Avoid caffeine
Likewise, do not drink caffeinated beverages before, during, or just after the flight. Caffeine can also cause dehydration and disrupt sleeping schedules. What’s more, caffeine can jangle your nerves and intensify any travel anxiety you may already be feeling.
Tip 6: Drink water
Drink plenty of water, especially during the flight, to counteract the effects of the dry atmosphere inside the plane. Take your own water aboard the airplane if allowed.
Tip 7: Move around on the plane
While seated during your flight, exercise your legs from time to time. Move them up and down and back and forth. Bend your knees. Stand upand sit down. Every hour or two, get up and walk around. Do not take sleeping pills, and do not nap for more than an hour at a time.
These measures have a twofold purpose. First, they reduce your risk of developing a blood clot in the legs. Research shows that long periods of sitting can slow blood movement in and to the legs, thereby increasing the risk of a clot. The seat is partly to blame. It presses against the veins in the leg, restricting blood flow. Inactivity also plays a role. It decelerates the movement of blood through veins. If a clot forms, it sometimes breaks loose and travels to the lungs (known as pulmonary embolism), lodges in an artery, and inhibits blood flow. The victim may experience pain and breathing problems and cough up blood. If the clot is large, the victim could die. Second, remaining active, even in a small way, revitalizes and refreshes your body, wards off stiffness, and promotes mental and physical acuity which can ease the symptoms of jet lag.
Tip 8: Break up your trip
On long flights traveling across eight, 10, or even 12 time zones, break up your trip, if feasible, with a stay in a city about halfway to your destination. For example, if you are traveling from New York to Bombay, India, schedule a stopover of a few days in Dublin or Paris. (At noon in New York, it is 5 p.m. in Dublin, 6 p.m. in Paris, and 10:30 p.m. in Bombay.)
Tip 9: Wear comfortable shoes and clothes
On a long trip, how you feel is more important than how you look. Wear comfortable clothes and shoes. Avoid items that pinch, restrict, or chafe. When selecting your trip outfit, keep in mind the climate in your destination time zone. Dress for your destination.
Tip 10: Check your accommodations
Upon arrival, if you are staying at a hotel, check to see that beds and bathroom facilities are satisfactory and that cooling and heating systems are in good working order. If the room is unsuitable, ask for another.
Tip 11: Adapt to the local schedule
The sooner you adapt to the local schedule, the quicker your body will adjust. Therefore, if you arrive at noon local time (but 6 a.m. your time), eat lunch, not breakfast. During the day, expose your body to sunlight by taking walks or sitting in outdoor cafés. The sunlight will cue your hypothalamus to reduce the production of sleep-inducing melatonin during the day, thereby initiating the process of resetting your internal clock.
When traveling with children, try to get them on the local schedule as well. When traveling east and you will lose time, try to keep the child awake until the local bedtime. If traveling west when you will gain time, wake your child up at the local time.
Tip 12: Use sleeping medications wisely or not at all
Try to establish sleeping patterns without resorting to pills. However, if you have difficulty sleeping on the first two or three nights, it’s OK to take a mild sedative if your physician has prescribed one. But wean yourself off the sedative as soon as possible. Otherwise, it could become habit-forming.