'Karoshi': Death from overwork, but what is 'overwork'?
Working over 55 hours weekly spikes stroke risk: study
Death from overwork?
Well, it’s not really overwork per se that kills. It's the knock-on effects – usually heart attack/stroke.
It turns out every piece of work has something to do with the human heart.
And those who pour their heart out for too long in their preoccupation for extended periods of time, could suffer "Karoshi" (literally "death by overwork"), considered a serious social problem in Japan.
The term "karoshi" has become part of the global business lexicon.
So, given the current work-90-hours-per-week-to-win-amid intense-global-competition business narrative, is it possible that the world could see a “tsunami” of “karoshi”?
What studies show
Mounting evidence from studies paints a stark picture: excessively long working hours can severely harm your health, cutting years off your life.
In 2019, the International Journal of Environmental Research and Public Health a “meta-analysis” of 243 records extracted from electronic health databases (from 1997 to 2018).
The study, led by Kapo Wong of the Department of Systems Engineering and Engineering Management at the City University of Hong Kong, showed that long hours led to the following adverse effects:
Cardiovascular disease risk
Chronic fatigue
Stress
Depressive state / anxiety
Poor sleep quality
Alcohol use and smoking
Self-perceived ill health
Mental health issues
Hypertension
Health behaviours, and
All-cause mortality.
Correlation
The correlation between overwork and heightened "mortality" rates, along with the risks of occupational injuries and chronic health conditions, underscores the dire consequences of ignoring the boundaries of sustainable work schedules.
Correlation (overwork) does not mean causation (death). Medically, it's usually heart failure that causes death from overwork, not the pressure of work itself.
It's a copout.
Consequences of karoshi:
Sudden deaths: Karoshi can cause sudden deaths and disabilities.
Workers' compensation: Families of victims are legally entitled to workers' compensation.
Higher mortality risk
Morever, a comprehensive UK-based "longitudinal" study analysed data from 414,949 individuals aged 20–64 years and found that men working more than 55 hours per week faced a significantly increased risk of mortality compared to those working standard hours.
Published in The Lancet, this study highlighted a direct link between prolonged work hours and cardiovascular health problems, including strokes and heart disease (Marmot et al., 2020).
Higher risk of heart disease
In another groundbreaking meta-analysis published in PLOS Medicine, researchers evaluated data from over 600,000 individuals across several countries.
They found that people working 55 hours or more weekly had a 33 per cent increased risk of stroke and a 13 per cent higher risk of developing coronary heart disease compared to those working 35–40 hours (Kivimäki et al., 2015).
Occupational injuries and safety risks
Occupational health experts have long noted the dangers of prolonged work hours.
According to a study published in the journal Occupational and Environmental Medicine, working 12 or more hours per day and 60 or more hours per week substantially increases the likelihood of workplace injuries and accidents, as fatigue, reduced focus, and impaired reaction times contribute to these elevated risks (Dembe et al., 2005).
The productivity-health paradox
While employers may believe that extended hours boost productivity, research paints a different picture.
The Harvard Business Review found that working beyond 50 hours per week delivers diminishing returns, and productivity sharply declines after 55 hours.
Instead of enhancing output, overwork undermines mental acuity and decision-making, potentially costing businesses more in errors and inefficiencies.
Some examples of karoshi:
A 22-year-old nurse who died from a heart attack after 34 hours of continuous duty five times a month
A 34-year-old man who worked 110 hours a week and died from a heart attack
A 37-year-old bus driver who worked more than 3,000 hours a year and died from a stroke
A 58-year-old man who worked 4,320 hours a year, including night work, and died from a stroke
Work-life balance
The narrative surrounding long working hours has kicked up a renewed debate. From corporate offices to industrial sectors, What's a "reasonable" work schedule in this day and age? What are the safeguards in place for employees’ health? And how to sustain productivity?
Researchers have called for safeguarding the occupational health of workers. Measures include mandatory-break policies, stricter regulations on overtime and encouraging time offs.
Policymakers were also encouraged to enforce and incentivise measures to curtail excessive work hours.
