JAPAN is witnessing a record number of compensation claims related to death from overwork, or “karoshi”, a phenomenon previously associated with the long-suffering “salary man” that is increasingly afflicting young and female employees.

Labour demand, with 1.28 jobs per applicant, is the highest since 1991, which should help Prime Minister Shinzo Abe draw more people into the workforce to counter the effect of a shrinking population, but lax enforcement of labour laws means some businesses are simply squeezing more out of employees, sometimes with tragic consequences.

Claims for compensation for karoshi rose to a record high of 1456 in the year to end-March 2015, according to labour ministry data, with cases concentrated in healthcare, social services, shipping and construction, which are all facing chronic worker shortages.

Hiroshi Kawahito, secretary-general of the National Defense Counsel for Victims of karoshi, said the real number was probably 10 times higher, as the government is reluctant to recognise such incidents.

Kawahito, a lawyer who has been dealing with karoshi since the 1980s, said 95 per cent of his cases used to be middle-aged men in white-collar jobs, but now about 20 per cent are women.

Japan has no legal limits on working hours, but the labour ministry recognises two types of karoshi: death from cardiovascular illness linked to overwork, and suicide following work-related mental stress.

A cardiovascular death is likely to be considered karoshi if an employee worked 100 hours of overtime in the month beforehand, or 80 hours of overtime in two or more consecutive months in the previous six.

A suicide could qualify if it follows an individual’s working 160 hours or more of overtime in one month or more than 100 hours of overtime for three consecutive months.

Work-related suicides are up 45 per cent in the past four years among those 29 and younger, and up 39 per cent among women, labour ministry data show.

* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or MensLine Australia 1300 78 99 78