Sleep Loss and Fatigue in Shift Work and Shift Work Disorder

Shift work is highly prevalent in industrialized societies. When it includes night work, it has pronounced negative effects on sleep, subjective and physiologic sleepiness, performance, accident risk, and health outcomes such as cardiovascular disease and certain forms of cancer. The reason is the conflict between the day-oriented circadian physiology and the requirement for work and sleep at the "wrong'' biologic time of day. Although some countermeasures may be used to ameliorate the negative impact of shift work on nighttime sleepiness and daytime insomnia (combined countermeasures may be the best available), there seems to be no way to eliminate most of the negative effects of shift work on human physiology and cognition.