World Day for Safety and Health at Work 2013

Case Study: Karoshi: Death from overwork

What Is Karoshi?

Karoshi is a Japanese word meaning death from overwork. This term has been used since the 1970s. In 1978 there was a report on 17 karoshi cases at the 51st annual meeting of the Japan Association of Industrial Health. Karoshi is not a pure medical term but a sociomedical term that refers to fatalities or associated work disability due to cardiovascular attacks (such as brain strokes, myocardial infarction or acute cardiac failure) aggravated by a heavy workload and long working hours. The phenomenon was first identified in Japan, and the word is now adopted internationally. The media have frequently used the word because it emphasizes the sudden deaths (or disabilities) caused by overwork which should be compensated. Karoshi has become an important social problem in Japan.

Here are some typical cases of Karoshi:
  1. Mr A worked at a major snack food processing company for as long as 110 hours a week (not a month) and died from heart attack at the age of 34. His death was approved as work-related by the Labour Standards Office.
  2. Mr B, a bus driver, whose death was also approved as work-related, worked more than 3,000 hours a year. He did not have a day off in the 15 days before he had stroke at the age of 37.
  3. Mr C worked in a large printing company in Tokyo for 4,320 hours a year including night work and died from stroke at the age of 58. His widow received a workers’ compensation 14 years after her husband’s death.
  4. Ms D, a 22 year-old nurse, died from a heart attack after 34 hours’ continuous duty five times a month.
Karojisatsu (suicide from overwork and stressful working conditions) has also become a social issue in Japan since the latter half of the 1980s. Long work hours, heavy workloads, lack of job control, routine and repetitive tasks, interpersonal conflicts, inadequate rewards, employment insecurity, and organizational problems could become psychosocial hazards at work.

Some causes of overwork or occupational stress include the following:
  1. All-night, late-night or holiday work, both long and excessive hours. During the long-term economic recession after the collapse of the bubble economy in 1980s and 1990s, many companies reduced the number of employees. The total amount of work, however, did not decrease, forcing each employee to work harder.
  2. Stress accumulated due to frustration at not being able to achieve the goals set by the company. Even in economic recession, companies tended to demand excessive sales efforts from their employees and require them to achieve better results. This increased the psychological burden placed on the employees at work.
  3. Forced resignation, dismissal and bullying. For example, employees who have worked for a company for many years and believed that they are loyal to the company, were suddenly asked to resign because of the need for staff cutbacks.
  4. Suffering of middle management. They were often in a position to lay off workers and in a dilemma between the corporate restructuring policy and protecting their staff.
These middle managers responsible for persuading workers to resign had to bear fierce protests from the targeted workers, suffered from emotional pain, and finally committed suicide.
The following figure shows the increase in number of approved cases of workers' accident compensation insurance benefit for Karoshi and Karojisatsu. It shows, there has been an increasing trend in cases of Karoshi and Karojisatsu in Japan. In 14 years, from 1997 to 2011, compensated cases of Karoshi and Karojisatsu have risen from 47 to 121 and from 2 to 66, respectively.

Measures to prevent Karoshi and Karojisatsu
  1. To reduce working hours and excessive work: Efforts to reduce working hours, working late at night and holiday work are indispensable in preventing excessive workload and work hours.
  2. To provide adequate medical support and treatment: Companies, families and society as a whole should work to improve the level of medical support and access to appropriate medical facilities and counselling mechanisms to prevent Karoshi and Karoujisatsu. Surveys on worker suicide show that most people commit suicide after suffering from a certain degree of mental disorder such as depression. Committing suicide is one aspect of this disease.
  3. To promote active and effective dialogue between workers and employers to design healthy and efficient work procedures and workplaces. Regular OSH committee activities or risk assessment activities implemented jointly by employers and workers should be useful in reducing the risk of overwork and work-related stress.
Ministry of Health, Labour and Welfare, Japan. 2011. Survey of work-related diseases. Available at: [4 Mar. 2013].
Ministry of Health, Labour and Welfare, Japan. 2012. Occupational disease recognition of mental disorders. Available at:[4 Mar. 2013].
Karoshi and Kaojisatsu in Japan, ASIAN LABOUR UPDATE 52, [4 Mar. 2013].