Almost exactly two years ago, I had open heart surgery. They sawed my rib cage open, peeled it back, stitched and reconnected things, bolted me back up. I was immobile for three weeks and didn't feel halfway normal for six months. It was a hideous experience but, all things considered, was better than the alternative, which was being dead.

What does this have to do with the workplace? Bear with me. Turns out I had none of the behaviors that lead to heart disease. I wasn't overweight, I had good diet, took reasonable exercise, didn't smoke, and so forth. What I did have, however, was a lot of workplace stress.

Now, psychologists have long known that some workplaces are particularly stressful. And physicians have long known that workplace stress can result in heart disease (a.k.a. CVD or cardiovascular disease). What wasn't known, however, is which elements of workplace stress are the most likely to cause CVD. Lousy bosses? Tight deadlines? Noisy offices? We just didn't know...until quite recently.

According to study of 412,000 U.S. workers published in International Journal of Environmental Research and Public Health, the workplace characteristic most likely to cause heart disease is mistrust. Julie Ray of the global analytics and advice firm Gallup explains the study's conclusion:

After the authors adjusted for demographic factors and whether respondents had health insurance, they found that trust was associated with seven CVD risk factors among both women and men in the sample. Workers who do not work in an open, trusting environment had greater odds of having high blood pressure, high cholesterol, and diabetes. [emphasis mine]

This finding is incredibly important because a certain amount of workplace stress is inevitable, making it difficult to know where to start to fix the problem. Pinpointing mistrust as the primary culprit, however, gives us a handle on what work environments to avoid, well, like the plague.

Consider this: Mistrust can exist even inside workplaces that are outwardly supportive. Indeed, arguably the worst bosses are the psychopaths who'll smile to your face then stab you in the back. It's stressful even to think about that kind of behavior.

By contrast, trust can exist even inside workplaces where, for example, CEOs throw frequent temper tantrums. Apple under Jobs is a perfect example of this. Jobs, by all accounts, acted like a jerk, but his people deeply trusted him.

So it really comes down to this: If you value your life, you should seek to leave any organization where you fundamentally don't trust your manager. Your long-term health literally depends upon it.

Take it from somebody who learned about stress the hard way.