By definition, jet lag is a temporary sleep disorder associated with extreme tiredness and other physical effects due to quick travel across multiple time zones.
Despite what most people think, jet lag is not caused by lack of sleep. Jet lag occurs when the body's internal clock (also known as your circadian rhythm), stays in your home time zone while you are physically in another time zone. This causes your body and circadian rhythm to be out of sync, leading to the side effects travelers despise so much. The primary symptoms are daytime fatigue, difficulty performing usual tasks, stomach problems and disturbed sleep—the longer the distance, the more intense the symptoms tend to be and the longer they tend to last.
Dr. Allison T. Siebern, a fellow in the Insomnia and Behavioral Sleep Medicine Program at the Stanford University Sleep Medicine Center, says cues (such as light exposure, mealtimes, social engagement and activities) help regulate circadian rhythms and keep your body on track.“When you cross time zones, it disrupts those [cues], and your internal clock and the external time are desynchronized. Your body needs to get on the rhythm of the new time zone,” says Dr.Siebern.
Thankfully, jet lag is temporary—but that does not necessarily help much on your vacation. For each time zone crossed, it can take up to a day for your body to adjust to the local time, and itis typically worse when traveling from west to east.
Older adults often suffer the most when it comes to adjusting to a new time zone. However, jetlag can affect anyone, although it might look different due to our individual physiologies. There are many things we cannot control about jet lag, but there are also quite a few steps we can take before and after a trip to lessen the effects, and make traveling more enjoyable from start to finish.