Shift work sleep disorder

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. Insomnia can be the difficulty to fall asleep or to wake up before the individual has slept enough. The excessive sleepiness appears when the individual has to be productive, awake and alert. Both symptoms are predominant in SWSD. There are numerous shift work schedules, and they may be permanent, intermittent, or rotating; consequently, the manifestations of SWSD are quite variable. Most people with different schedules than the ordinary one (from 8 AM to 6 PM) might have these symptoms but the difference is that SWSD is continual, long-term lasting and starts to interfere with the individual's life, like the social life and the professional life. 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. Insomnia can be the difficulty to fall asleep or to wake up before the individual has slept enough. The excessive sleepiness appears when the individual has to be productive, awake and alert. Both symptoms are predominant in SWSD. There are numerous shift work schedules, and they may be permanent, intermittent, or rotating; consequently, the manifestations of SWSD are quite variable. Most people with different schedules than the ordinary one (from 8 AM to 6 PM) might have these symptoms but the difference is that SWSD is continual, long-term lasting and starts to interfere with the individual's life, like the social life and the professional life. There have been many studies suggesting health risks associated with shift work. For example, a 2007 study led by the IARC (International Agency for Research on Cancer) showed that shiftwork has been associated with cancer. Other studies have reported that night workers have an increased incidence of heart disease, digestive disorders and menstrual irregularities. Michael Lee et al. demonstrated that those working night shifts had a significantly higher risk of hazardous driving events when compared to those on a typical day shift schedule. Because a formal diagnosis of SWSD was not typically made in these studies, it remains unclear whether the reported risks apply to the subset of shiftworkers who qualify for a diagnosis of SWSD or apply to all shiftworkers. SWSD can increase the risk of mental disorders like depression or other mood issues. The circadian system regulates the rate of chemical substances in the body, but if this system is impaired, several consequences are possible. They can affect the individual's social life and cause a lack of well-being and happiness. Alcohol or drug use disorder can also be risk factors, which might also worsen the situation. Having a lack of sleep can impact cognitive performance. For example, it might become difficult to stay focused and concentrate, and reaction times might also be slowed down. All these factors can affect work efficiency and cause accidents. All these consequences are dangerous for the individual but also for others, as many jobs involve taking care of or protecting others. In addition, SWSD might interfere with making decisions quickly, driving, or flying safely. To promote a healthy lifestyle, the American Academy of Sleep Medicine recommended that an adult have 7 or more hours of sleep per day. Each year there are almost 100,000 deaths estimated in the U.S. because of medical errors. Sleep deprivation and sleep disorders are factors that contribute significantly to these errors. In the same article, the authors affirm that there is a high prevalence of unsleepiness and symptoms of sleep disorders related to the circadian system in medical center nurses. In a study done with around 1100 nurses, almost half of them (49%) reported sleeping less than 7 hours per day compared to national figures, in which 28% of people claimed to sleep less than 7 hours per night. In this sample of nurses, 27% used medication as a help to sleep and 13% used medication to stay awake. In addition, 31% of the sample suffer from chronic insomnia and 4.5% have excessive sleepiness. Insomnia and wake-time sleepiness are related to misalignment between the timing of a non-standard wake–sleep schedule and the endogenous circadian propensity for sleep and wake. In addition to circadian misalignment, attempted sleep at unusual times can be interrupted by noise, social obligations, and other factors. There is an inevitable degree of sleep deprivation associated with sudden transitions in sleep schedule. The prevalence of SWSD is unclear because it is not often formally diagnosed but it is estimated to affect 5-10% of night and rotating workers. There are various risk factors, including age. Although SWSD can appear at any age, the highest prevalence is in the 50 years old and above age bracket and even more so in cases of irregular schedules. Gender is also a factor . It may be that female night workers sleep less than their male counterparts . A possible explanation is the social obligations that can increase their vulnerability to SWSD. Female night workers also seem to be more sleepy at work.