Health Effects of Working Night Shift
Working night shifts can disrupt many of the body’s natural systems. One of the main reasons for this is the disruption of the body’s circadian rhythms.
Circadian rhythms are driven by the in-built clocks that exist in every cell of your body, running on a roughly 24-hour cycle. They play a key role in regulating hormone production and release, hunger and metabolism, body temperature, heart rate, and blood pressure. For shiftworkers, maintaining synchronisation is a challenge. Irregular work schedules mean exposure to light, eating, and sleeping often happen at times that conflict with your natural circadian rhythms – this is called circadian disruption. As a result of this disruption, shiftworkers are at higher risk of a range of issues related to sleep, health, and wellbeing.
Health Effects of Night Shift Work
Shiftwork poses significant challenges to sleep, leading to various health and wellbeing issues. Among the most common problems associated with inadequate sleep in shiftworkers are:
Overweight and obesity: Shiftworkers are 2–3 times more likely to become overweight or obese, linked to inadequate sleep and circadian disruption.
Diabetes: Shiftworkers are 1.5–2 times more likely to develop Type 2 Diabetes, linked to inadequate sleep and circadian disruptions.
Heart disease and stroke: Shiftworkers, particularly those who work a lot of night shifts, have a 16–24% increased risk of developing heart disease, directly due to inadequate sleep. For every 5 years of shiftwork, there is an estimated 4% increase in risk of stroke.
Cancer: The World Health Organisation has deemed that shiftwork, specifically night shift, is a probable carcinogen. For example, people with more than 30 years of shiftwork experience are 36% more likely to develop breast cancer.
Night Shift & Sleep: Sleep is a key pillar of health. Healthy adults typically need 7–9 hours of quality sleep in each 24 hours. For shiftworkers, consistently hitting this target can be a challenge, especially when your schedule demands that you’re awake and active at unconventional hours – for example, sleeping during the day and then working overnight. Some studies show that up to half of all shiftworkers don’t get enough sleep.
Wellbeing Impacts
Poor sleep and circadian disruption can also impact wellbeing and quality of life.
Short-term impacts: Even just one day of poor sleep can immediately impact emotional regulation, pain tolerance, cognitive speed, and memory.
Mental health: Shiftworkers are more prone to depressive symptoms, anxiety, and mood instability.
Job satisfaction: Lower job satisfaction and higher workplace stress are common amongst shiftworkers.
Relationships: Challenges in maintaining healthy personal relationships, including with partners and children, are often noted by shiftworkers.
Fatigue and Safety
Fatigue related to inadequate sleep can also increase safety risks.
During shifts: Fatigue leads to increased workplace errors, accidents, and injuries, sometimes up to three times more than non-shiftworkers.
After shifts: Shiftworkers have a 30% higher likelihood of car accidents during commutes.
Looking After Your Health as a Shiftworker
You may not feel the impacts of inadequate sleep immediately, but over time they can build up and contribute to major health and wellbeing problems. Alongside nutrition and physical activity, looking after your sleep as a shiftworker will help you to stay healthy and well, both now and into the future.