The Job Stress Index 2014 concluded that two million of the 4.9 million workers in Switzerland suffer from too much work.
The survey, conducted by researchers at the University of Bern and the University of Zurich, also found that more than one million workers say they are stressed by their jobs.
The study said that people working full-time and young workers are most affected by stress, while men and woman are equally affected.
The pressure of deadlines, too much work and problems with superiors and colleagues are among the key factors causing stress, the report said.
Job satisfaction, emotional ties with the employer, the support of superiors and flexibility are among the elements enjoyed by workers without stress.
Those suffering from stress have more problems with sleep, are more easily irritated and in general have poorer health than workers who report not feeling any stress, the report said.
Stressed employees are more likely to be absent from their jobs and less productive while working, it said.
The overall related cost to Swiss businesses from absences, lost productivity, reduction in time worked and staff turnover was estimated at 5.6 billion francs ($5.9 billion) per year.
The results of the study are based on a survey of 3,484 workers throughout Switzerland in February this year.