≪ Shift workers are employees who work in shifts divided into two or more groups, each working at different times. Since shift workers may perform night shifts between 10 PM and 6 AM the following day, they are at risk of sleep disorders, chronic fatigue, high blood pressure, and cerebrovascular diseases due to disruptions in their circadian rhythms. Therefore, it is crucial to pay attention to work and health management for these workers. ≫
The human body operates on a 24-hour cycle known as the circadian rhythm. For shift workers, changes in biological cycles and disruptions in circadian rhythms can occur, affecting hormone and metabolic functions, cell proliferation, and cognitive abilities. This can lead to health issues such as chronic fatigue, high blood pressure, dyslipidemia, cerebrovascular diseases, sleep disorders, and various types of cancer.
Additionally, workers who start their shifts before 6 AM or work late at night may experience sleep disorders. Sufficient lighting is essential during night shifts to improve work efficiency and ensure worker safety. However, exposure to bright lights can suppress melatonin production in the brain, thereby increasing the risk of cancer.
The secretion of gastrin and pepsinogen, major factors in the development of peptic ulcers, is also promoted, increasing the risk of gastrointestinal diseases. Shift work has a higher error rate and serious accident rate during night shifts compared to daytime work, as workers are less responsive to signals.
To minimize disruptions to circadian rhythms, it is advisable to set night shift change times before midnight, as shift changes before 7 AM can cause biological rhythm disturbances. Shift rotations should follow a forward direction (morning shift → evening shift → night shift), and continuous or fixed night shifts should be reduced. Avoid continuous night shifts for more than three days and fixed night shifts, and minimize two-shift work.
Accident rates increase when the rest period between a night shift and the next shift is less than 24 hours. Short rest periods of 7-10 hours, such as transitioning from a day shift to an evening shift within the same calendar day, are risky. Particularly after night shifts, ensure a minimum rest period of 24-48 hours before the next shift. Additionally, shift and night workers should have more annual leave than daytime workers.
Shift workers should rest on weekends rather than weekdays and take breaks between 3 AM and 5 AM, the period when fatigue is most strongly felt during night shifts.
Shift work alters lifestyle patterns, which can reduce interactions with family and friends and increase mental stress. To mitigate this, maintaining appropriate social relationships and engaging in healthy hobbies to support mental and physical health is recommended.
Shift workers should regularly monitor their weight, fatigue, sleep, and gastrointestinal symptoms. If weight loss exceeds 3 kg in a month, they should undergo a thorough medical examination. Older workers are more prone to dehydration, so they should consume drinks and supplements during night shifts. It is advised that new mothers avoid night shifts for at least one year postpartum. When driving home after a night shift, practice defensive driving, and prevent drowsy driving by listening to music or conversing with a passenger.
For daytime sleep after a night shift, go to bed as soon as possible. Shift workers should inform their families of their shift schedules to help create an environment conducive to uninterrupted sleep. While individual needs vary, it is generally recommended to get at least six continuous hours of sleep.
Avoid exercising within four hours before bedtime, as excessive activity can interfere with falling asleep quickly and hinder fatigue recovery. Regular relaxation techniques and meditation can also aid in adapting to sleep and shift work.
Before sleeping after a night shift, avoid overeating, coffee, and alcohol, as they can burden the digestive system and disrupt sleep. Excessive consumption of tobacco and caffeine can exacerbate gastrointestinal issues and sleep disorders, so caution is advised. Particularly, drinking alcohol to overcome insomnia can rapidly deteriorate health, so it is important to avoid this practice.