Death from overwork is not limited to Japan, however. Other Asian nations such as China, South Korea and Bangladesh have reported similar incidents. In China, where this phenomenon is called guolaosi, an estimated number of 600,000 people died from overwork every year in past years . Increasingly, Chinese workers are organizing and demanding better work conditions. In South Korea, where the work ethic is Confucian-inspired, and work usually involves six-day workweeks with long hours, this phenomenon is called gwarosa.

In Japan, the number of cases submitted for compensation has increased significantly in the last few years. So has the number of court cases when the government refuses to compensate the victims' families. In Japan, if a death is considered karoshi, surviving family members may receive compensation from the government and up to $1 million from the company in damages. However, death may be only the tip of the iceberg of this phenomenon, just the most visible effect of overwork in Japan.

The causes and consequences of karoshi have been particularly studied in Japan, where the National Defense Council for Victims of Karoshi was established in 1988. Japan, has much longer working hours that any other developed country. The country's grueling work schedule has been suggested as one of the main causes of karoshi, but it is not the only cause.

A growing body of evidence indicates that workers in high demand situations, who also have low control of their work and who have low social support have an increased risk of developing and dying of cardiovascular disease, including myocardial infarctions and stroke. Stressful work conditions are a critical component of this phenomenon. In this regard, it has been found that workers exposed to long overtime periods show markedly elevated levels of stress hormones.

The consequences of long working hours and stressful situations at work are not limited to men. Several studies have shown strong links between women's work stress and cardiovascular disease. In the Women's Health Study - a landmark study involving 17,000 female health professionals - a group of Harvard researchers found that women whose work is highly stressful have a 40 percent increased risk of heart disease compared with their less stressed colleagues.