Jet Lag is a physiological condition that appears when a person travels by airplane or jet across time zones and their circadian cycle becomes altered. When a person travels to a different time zone their circadian cycle becomes altered because they are accustomed to certain hours of the day with daylight and night time and traveling across time zones changes the time and the time when the sun is to set or rise.

Many patterns become upset when jet lag occurs. The rhythms and times that dictate eating, sleeping, hormonal regulation and body temperature regulations no longer relate to the environment. For some people it may take several days to get over jet lag but for others it may take one or less than one day.

There are some symptoms to jet lag including loss of appetite, digestive problems, nausea, headache, sinus irritation, fatigue, and mild depression.

Working the night shift has many effects on the human body. A person working the night shift can cause a person to become more at risk for heart disease, mood disorders and psychological disorders. A person working the night shift does not experience sunlight which keeps bodily functions working during the day but at night these shut down.

When you first start to work the night shift your circadian cycle becomes completely messed up. You try to sleep when you are wanting to be getting up and you have to get up when you are just wanting to close your eyes and go to sleep. It is very difficult for a person to get on a healthy routine for working the night shift. Working during the nighttime hours is a difficult task but sleeping during the daylight hours is even more difficult.

Stöppler, M. C. (n.d.). Jet Lag Causes, Symptoms, Treatments. Retrieved January 4, 2009, from http://www.medicinenet.com/jet_lag/article.htm
Night Shift (2004, November 14). Retrieved January 4, 2009, from http://www.nightowlcafe.com/Flow/Nightshift.htm