Bad bosses are killers. Literally.

A Swedish study has found that the more workers feel that their bosses are incompetent, the more the workers' risk for heart attacks, heart disease, angina and death from heart related causes rises. This risk increases the longer one works in the same stressful environment.

This type of correlational study can never show causality... It can only show that bad bosses and heart trauma seem to occur together, like death and taxes.

The researchers define a good boss as one having consideration for employees, setting clear goals, setting realistic expectations, communicating and giving feedback, managing change, including people in decision-making and delegating authority. A bad boss tends to lack these qualities.

Anna Nyberg, a psychologist and doctoral student at the Karolinska Institute's Department Of Public Health Sciences, headed the study. Her team analyzed data from 3,100 men, aged 17-70, who participated in a Stockholm study on work, lipids and fibrinogen between 1992 and 1995. Nyberg's team then matched this information with hospital records of the workers up to the year 2003. The team found 74 instances of fatal and non-fatal heart attacks, angina and death from heart disease. The results of this study were published in the November 25, 2008 online edition of Occupational and Environmental Medicine.

This type of Correlational study study can never show causality: that bad bosses cause heart trauma. It can only show that bad bosses and heart trauma seem to occur together, like death and taxes.

According to Nyberg, "This study suggests that managers have key roles in determining stress-related factors at work, which means that psychosocial work environment interventions could be directed towards managers in order to reduce stress in employees."

In other words, somebody should do something about bad bosses.

So how does one deal with a bad boss? Entire books have been written on the subject and there isn't one single, clear answer. Resist the allure of responding in anger. That will just take an even greater toll on your heart. Cooler heads should prevail here.

A reasonable first step is probably to try to talk to your boss about the situation. Yes, if your boss was someone you could talk to, they wouldn't be such a bad boss, but it's worth a try. Your boss may simply not understand how deeply some of his or her actions are affecting you. If you have colleagues or co-workers who seem to get along well with your boss, ask them how they manage this feat. It may be that your boss triggers something in you in particular. If their interactions with your boss aren't as overwhelming to them as yours are to you, they may be able to offer a useful suggestion or two.

If nothing you try seems to improve the situation, the best approach may be to learn to count slowly to a million by twos and to make sure that your resumé is up to date.