Jetlag – Causes, Symptoms, Prevention and Treatment

Jet lag (desynchronosis) occurs while rapidly crossing time zones, or, more specifically, it occurs after crossing the Earth's meridians. Meridians demarcate geographic position in relation to the Earth's poles and, ultimately, define time zones. Jet lag is a unique sleep disorder because its onset is not necessarily caused by abnormal sleep patterns, like insomnia.

Travelers who sleep normally prior to transmeridian travel are not immune to jet lag; the symptoms result when a person's internal clock attempts to acclimate to a new external environment. This acclimation involves circadian rhythms that, among other functions, are associated with the body's management of sleep.

Symptoms
The feelings of disorientation encountered as a result of crossing time zones are known as jet lag. Symptoms include fatigue and general tiredness, inability to sleep at night, loss of concentration, loss of drive, headaches and general malaise. Jet-lag occurs when biological rhythms are disrupted as a result of rapid transitions across multiple time-zones. Such desynchronization of rhythms also occurs in nocturnal shift work employees who transfer to night shifts.

Causes
Traveling through a few time zones at a time is not as disruptive to circadian rhythms as traveling around the world can be. The foremost symptom of jet lag is altered sleep pattern—sleepiness during the day, and insomnia during the night. Jet lag may also include indigestion and trouble concentrating. Individuals afflicted by jet lag will alternate in and out of a normal day-night cycle.

Your body contains it's own internal clock which is powered by the environment around you including such things as temperature, humidity and, in particular, the normal daily change between daylight and darkness. These environmental factors cause your internal clock to run, rather like a normal clock, on a series of 24 hour cycles, sometimes referred to as your body's circadian rhythms.

Here are some tips to help prevent jet lag:
Maintain a sensible bedtime schedule prior to your trip. Don't avoid sleeping in order to make yourself tired.
Go to bed earlier for a couple of nights before leaving if you are traveling east. Go to bed later for a couple of nights if you are traveling west.
For short trips, maintain a schedule of eating and sleeping at your usual time, if possible, while at your destination.

Drink a lot of water. Avoid alcohol and coffee, which dehydrate the body. Also, avoid herbs like ginkgo, which can cause restlessness.

Treatment
Melatonin is the hormone that controls your body clock. Normally, your brain produces melatonin during the night to help you sleep. Your body starts to make melatonin when it gets dark, and stops when it gets light. The melatonin that's sold as a treatment is a man-made version of this hormone.

A controversial treatment for jet lag is melatonin, a synthetic human hormone that promotes sleep. Several studies have shown that melatonin can alleviate jet lag. When melatonin was examined in scientific studies, eight of the 10 trials found that taking melatonin close to the target bedtime at the destination (10 p.m. to midnight) decreased jet lag from flights crossing five or more time zones. However, other studies show little or no benefit to melatonin in preventing jet lag.