Human body possesses a body clock (med. circadian rhythms) which is in charge of the timing of routine functions like sleeping and eating. Flying through different time zones has a disruptive effect on the body clock, and adjusting to the new rhythm of night and day sometimes takes days, which is known as jet lag. Jet lag symptoms can vary from person to person, but generally, people feel tired and have difficulties falling asleep at right hours. Some are very lively and energetic during nighttime, while they experience fatigue in the daylight. Jet lag is also marked by a number of symptoms including fatigue, irritability, poor memory and concentration, poor appetite, indigestion, disruption of bowel habits, clumsiness, headaches and the general feeling of being unwell.
Thanks to the body clock, people are used to a day and night cycle typical of their time zone, and when found in a different time zone, this interferes with the body’s circadian rhythms. There are 24 time zones in the world, and this division is based around Greenwich meridian in London, UK. Each hour corresponds to 15 degrees of distance from the Greenwich, and jet lag risk occurs when more than 3 time zones are travelled. Children and babies usually don’t suffer from jet lag since they have no trouble sleeping at any time, while the elderly and people with a strict routine are severely affected by it. Travelers suffering from anemia, heart and lung conditions are advised to contact their doctor and the airline before departure, because the air pressure in the cabin is lower than normal, so the body doesn’t receive enough oxygen. Healthy individuals are not affected by this.
Jet lag is diagnosed according to the symptoms and the number of time zones traveled, and it is possible to roughly determine how many days a person is going to be suffering from it. Here are some tips on jet lag prevention. Before the actual flight, people are advised to get up and go to bed earlier if traveling east, and get up and turn in later if flying west. During the flight, people should take plenty of non-alcoholic and non-caffeinated drinks, move around as frequently as possible and adjust their watches to the time zone of the destination as soon as they board the plane. On arrival, passengers are recommended to spend the day outside in the natural light, exercise every day and try to establish a daily routine. Distant country journeys lasting one or two days don’t give the body enough time to adjust, so advice for business people is to try to arrange important meetings at the time coinciding with the daytime at home.
The use of medicines in jet lag prevention and treatment has not been confirmed by substantial research. Human brain produces a hormone called melatonin which informs the body when it is time to sleep, but although melatonin supplements are available on the market, they are not recommended for use. Doctors can provide advice on the exposure to bright sunlight or the special bulb light, which reduce symptoms of jet lag. If suffering from diabetes or taking contraceptive pill, doctor’s should also be consulted about the time medication is supposed to be taken.