By Elizabeth Cohen Senior Medical Correspondent
(CNN) -- Workplace stress isn't just annoying -- it's as bad for your health as secondhand smoke, according to a new study by researchers at Harvard Business School and Stanford University.
"When you think about how much time individuals typically spend at work, it's not that surprising," says study co-author Joel Goh, an assistant professor of business administration at Harvard Business School.
The report compiled evidence from 228 other studies, and found that high job demands increased the odds of having an illness diagnosed by a doctor by 35%. Long work hours increased the chances of early death by almost 20%.
By far the biggest stressor was the worry that you might soon lose your job; that increased the odds of having poor health by about 50%.
Goh said he hopes his study will help companies think about the way they manage their employees. He said it might seem like demanding faster work or longer hours would increase productivity, but that might not be the case.
While employers might do their part to reduce stress, here's what the rest of us can do.
Keep a work stress journal
The experts at the Mayo Clinic advise writing down when you feel stressed. Was it during conversations with a particular person, for example? It may not be your job, but an individual who's causing problems, and you need to think about better ways of dealing with him or her.
Do a reality check
As the Harvard study showed, the biggest stressor is the worry that you might lose your job. Ask yourself if your job is really in jeopardy, or if it's just something you've concocted in your head. Asking fellow employees for their perspectives could help.
Ask yourself, do I really like my work?
Joanna Lipari, a psychologist in Los Angeles, has found that patients who love their work deal with stress much better than those who don't. "People who believe in what they're doing handle stress better than those who don't," she said. If you don't love your work, it might be time to think about finding work that really does make you happy.
Think through the worst-case scenario
Afraid you're going to lose your job? What would you do if you did? Lipari advises taking those steps now. If you think you would write a new resume or reach out to former colleagues to see if they're hiring, then do that now.
Set limits with your boss
If your boss wants you to work 10-hour days instead of eight-hour days, tell him or her you can't, but then go on to explain all the work you complete in your eight-hour day. "Make it about being project-oriented, not time-oriented," Lipari says.
TM & © 2015 Cable News Network, Inc., a Time Warner Company. All rights reserved.