Shift work sleep disorder (SWSD) is a circadian rhythm sleep disorder characterized by insomnia and excessive sleepiness affecting people whose work hours overlap with the typical sleep period. There are numerous shift schedules, and they may be permanent, intermittent, or rotating; consequently, the manifestations of SWSD are quite variable.
Shift work sleep disorder is trouble sleeping because you work nights or rotating shifts. You also may have this problem if you have trouble staying awake or alert when you are supposed to work your shift. You may not be able to sleep during the day, and you may not feel rested with the sleep you do get.
Shift work sleep disorder involves a problem with your body's 24-hour internal clock, or circadian rhythm. Light and dark help your body know when to be active and when to rest. Light is a cue to be awake, while dark tells your body to sleep. When you work at night and sleep during the day, your body's internal clock needs to reset to let you sleep during the day. Sometimes that's hard to do.
Shift workers have an increased risk of heart problems, digestive disturbances, and emotional and mental problems, all of which may be related to their sleeping problems. The number and severity of workplace accidents also tend to increase during the night shift. Major industrial accidents attributed partly to errors made by fatigued night-shift workers include the Exxon Valdez oil spill and the Three Mile Island and Chernobyl nuclear power plant accidents. One study also found that medical interns working on the night shift are twice as likely as others to misinterpret hospital test records, which could endanger their patients. It may be possible to reduce shift-related fatigue by using bright lights in the workplace, minimizing shift changes, and taking scheduled naps.
This sleep disorder usually is a problem for people who work all night. But people who work an early morning shift—for example, starting at 4 a.m.—also may have sleep problems. Rotating shift work also can be hard. In these shifts, people work the day shift on some days and the night shift on others.
Shift work can increase stress, and that may make you more likely to get sick. Lack of sleep from shift work can increase the chance of car accidents and on-the-job accidents. It also can lead to trouble concentrating at work and poor job performance.
Light is a powerful signal for your internal clock. Light therapy may help shift workers adjust to irregular schedules. Light has two primary effects on your sleep/wake pattern. It has an alerting effect, and it also has the ability to gradually shift sleeping patterns earlier or later, depending on the timing of light exposure. The time of day is very important to achieve the desired effect. Exposure to bright light early in a person’s wake period (and dim light at the end of the wake period) has the effect of moving the internal clock earlier. Exposure to light late in the day delays the timing of the internal clock. The timing of exposure to light can help you establish a better sleep/wake pattern, based on your work schedule and needs
Re-Timer provides a UV-free green light source shown in university trials to be the optimal wavelength to re-time the circadian rhythm, allowing you to achieve a sleep rhythm that is suitable to your shift.