Shift work sleep disorder (SWSD) is a sleep disorder that affects people what work irregular hours or in shift rotations. Their sleep schedules are required to deviate from the natural circadian rhythm of the body, which usually regulates the sleep-wake cycle.
As a result, their sleeping pattern is disrupted and they can have difficulty sleeping when they have time to sleep and may become sleep deprived and underperform at work due to excessive sleepiness.
It is most common in individuals that work unusual hours, usually between 10 p.m. and 6 a.m.
Shift work sleep disorder occurs due to a misalignment between the actual and desired sleeping pattern of the individual, usually as it differs from what is considered as normal by society.
It is classed as a circadian rhythm sleeping disorder, as it involves changes in sleep habits that differ from the normal sleep-wake cycle of the body. The circadian rhythm is the internal body clock that responds to light cues in the surrounding environment to regulate the production and release of hormones, causing an individual to feel tired and alert at specific periods during the day.
Between 15-26% of the labor force in the United States and similar developed nations work irregular hours, in the nighttime or in rotating shifts.
The vast majority of people who work in this manner can adjust and continue to perform well, despite changes in sleeping patterns. However, some individuals have significant difficulty adjusting their internal body clock accordingly and shift work sleep disorder can present. This occurs when there is a disparity between the sleep-wake cycles required by their work and circadian rhythm.
Despite the number of hours slept during the day, attempting to work when the circadian rhythm promotes sleep is extremely difficult if the internal pacemaker doesn’t change according to the needs of the individual.
Symptoms and Complications
The symptoms of SWSD commonly include:
- Difficulty sleeping at desired bedtime
- Excessive sleepiness during awake hours
- Reduced concentration and performance at work
Additionally, as the performance of affected individuals during the day is limited, there is an increased risk of workplace accidents and errors, sick leave and mood changes.
It is essential that people who work irregular hours or in shifts prioritize sleep and make arrangements to maximize sleep quantity and quality, even if it is at irregular hours.
Techniques to help aid the quality of sleep include:
- Minimize exposure to light shortly before planned bedtime
- Follow a bedtime ritual to prepare body and mind for sleep
- Allow sufficient time to sleep (at least 7-8 hours a day)
- Ensure there is a positive sleep environment (e.g. low light and sound)
- Reduce intake of caffeine, alcohol and nicotine before bedtime
It is also helpful for people that are having difficulty maintaining a regular sleep schedule to keep a sleep diary to record their habits and identify any particular problems that could be addressed.
In some cases, changes to the work environment may be needed. This may include decreasing the number of consecutive night shift or reducing the number of work hours. It is important that affected individuals feel that they have enough time to sleep, in addition to spending time with family and participating in other activities.
Prescription medications are also sometimes indicated to help in the management of SWSD. This may include stimulant drugs such as modafinil to increase alertness at work or sleep aids to help with sleeping.