What is jet lag?
Jet lag, also called desynchronosis, is a temporary disorder that causes fatigue, insomnia, and other symptoms as a result of air travel across time zones.

What are other symptoms of jet lag?
Besides fatigue and insomnia, a jet lag sufferer may experience anxiety, constipation, diarrhea, confusion, dehydration, headache, irritability, nausea, sweating, coordination problems, and even memory loss. Some individuals report additional symptoms, such as heartbeat irregularities and increased susceptibility to illness.

How does the body keep time?
A tiny part of the brain called the hypothalamus acts like an alarm clock to activate various body functions such as hunger, thirst, and sleep. It also regulates body temperature, blood pressure, and the level of hormones and glucose in the bloodstream. To help the body tell the time of day, fibers in the optic nerve of the eye transmit perceptions of light and darkness to a timekeeping center within the hypothalamus. Thus, when the eye of an air traveler perceives dawn or dusk many hours earlier or later than usual, the hypothalamus may trigger activities that the rest of the body is not ready for, and jet lag occurs

What are the treatment options for jet lag?
Because the experience of jet lag varies among individuals, it is difficult to assess the efficacy of any particular cure.

• Slow and gradual fine tuning - slow gradual fine-tuning during several days while maintaining the regular length of 7 to 8 hours of sleep can reduce tiredness and avoid depression. If the objective is to catch up with local time, it is recommended that the traveler refrains from taking naps during the afternoon. Eating an early dinner rich in carbohydrates and low in protein can be helpful.
   

• Light therapy - the body's internal clock or circadian rhythms are influenced by exposure to sunlight, among other factors. When someone travels across time zones, the body must adjust and reset to a new daylight schedule. This allows you to fall asleep and be awake at the appropriate times.
  
  Light therapy can help ease that changeover of jet lag. 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 are meant to be awake. This may be useful, for example, if you are a business traveler and are frequently indoors and away from natural sunlight.
   

• Caffeine - using caffeine in the amounts you encounter in beverages like coffee, espresso and soft drinks may help offset daytime sleepiness. However, it's best to time caffeine use so that it does not interfere with planned bedtime, because it may make it even more difficult to fall asleep or sleep soundly. Therefore it is essential not to consume any caffeine within six hours before planning to go to sleep.