Shift work, in particular night shift, disturbs the natural sleep-awake rhythm. At first, one usually has no problem adapting him/herself to the changed sleeping times. However, after long durations of shift work, it virtually always to comes problems.

The amount of sleep during the day is often not enough or is interrupted by external influences. Particularly with irregular shifts and unfavorable time management, the body increasingly has problems to adjust itself to the unnatural sleep times because the internal sleep-awake rhythm gets out of balance. Considerable problems to fall asleep and fatigue in the awake phase can develop into massive problems. Other physical illnesses and mood variations often arise also.

Jetlag (time zone change):

Intercontinental flights cross several time zones within a short time. The normal sleep-awake rhythm is thereby interrupted resulting in different, very distinct sleep disorders and/or fatigue during the day, often accompanied by other symptoms like stomach bowel discomforts etc. In times of growing travel activities, the meaning of this sleep disorder has increased.