Jet lag can occur when people fly across several time zones. This can caused when their circadian rhythm (their internal biological clock) is out of synch with the place they landed. Interestingly, sleep problems tend to be more common when people travel from west to east as it is more difficult to advance than to delay sleep time. Circadian rhythms are physical, mental and even behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness. Most animals and plants have them. The body’s master clock controls the production of melatonin, a pineal gland hormone found in animals, plants and bacteria that makes you sleepy. There is also a condition known as social jet lag which is related to the different sleep patterns that occur on weekends or work shift changes and is thought to be related to obesity.
Some have recommended taking melatonin for jet lag, but consult your physician about the dosage and which preparations are safe. However, to avoid jet lag, try the following: Gradually adjust your sleeping habits to your destination time zone a few days in advance. Set your watch to the new time zone when you get on board and try not to nap. Drink plenty of liquids to avoid dehydration. Do not sleep more than two hours immediately after arrival. Avoid social isolation. Try to get up early after the first night you landed and get some sunshine, as lack of light effects jet lag as well.
–by Dr. Howard Bellin