[Page 3155]Approximately 16% of the workforce consists of shift workers, and the prevalence of shift work disorder (SWD) in the general population may be as high as 2% to 5%. Shift work refers to anything outside the traditional daytime work schedule. It usually affects people who work nights, but it can also affect those who start work early, before 6:30 a.m., or in the evening, after 4:30 p.m. SWD creates problems with excessive sleepiness during the work shift combined with insomnia during the times the patient wants to sleep. Symptoms may include headaches, weight gain, gastrointestinal issues, fatigue, attention or concentration issues, irritability, and depression. This entry discusses the risk factors for developing SWD and treatment options.

The human body is programmed through circadian rhythms to ...