This is the second most popular sleep disorder and usually affects international flights and if it's domestic if they're going between time zones. This is what you call knocking your body clock out of synch because when you're traveling across different time zones especially at the international level because that can throw you off an entire day if you're coming from the west going east from New York to London or Los Angeles to Tokyo or Sydney which can throw you off since you cross the international date line which is one day ahead and behind.

It seems as if women are more affected than men and according to medical reports its because the natural hormone estrogen and it's triggered when the body when accustomed to normal daytime and nighttime rhythms therefore you're upsetting the body's natural state of corresponding with a specific time of day and it can even interrupt eating patterns as well. It can take up to several days to even a full week to regain some normalcy on the time and place once you've had time to sleep yourself into adjustment mode.

The symptoms of jet lag vary by the individual person and symptoms can include or be a combination of dehydration which can trigger minor disorientation, and loss of appetite, headaches and sinus irritations, fatigue, grogginess, nausea and/or vomiting from an upset stomach, irritability, and mild depression. Jet lag is not linked to the length of a flight, but the transmerdian distance traveled. For example if you flew from New York and Los Angeles which is approximately 5 hours you will feel some jet lag crossing the Central and Mountain time zones. Jet lag can be extremely difficult in places like Alaska and Russia because of the fact that Alaska only sees a short amount of daylight and Russia has 11 different time zones and can really throw someone off if they were flying from Copenhagen to Tokyo.

Usually people that are prone to this are often given sedatives by their doctors to help them sleep through the flight and to wake up without the effects of jet lag when they land in their destination.

Ways to recover quicker from jet lag is proper nutrition, exercise, and sleep because you'll be surprised to know that people who don't sleep or get enough rest and relaxation will deal with it later when they land and the disorientation sets in. Sunlight according to doctors say can help reset your body's clock back in synch.

It's difficult to pinpoint the severity of jet lag because it affects people differently and usually people who travel on international flights are less likely to deal with jet lag because they're used to the constant change. And have manage to adapt to those changes since some travel monthly for business and usually it's business travelers who deal with jet lag more than those who go for vacations.

Business travelers fly at odd times which can throw someone off because they're flying out super early or catching the red eye somewhere to arrive the next day.