Stress is a contagion. Like an airborne disease, it can spread from one person to another through casual contact.

According to University of California, Riverside researchers Howard Friedman and Ronald Riggio, stress can be transmitted through verbal and nonverbal expressions. If someone who is stressed out comes into your visual field, you can start to experience stress yourself, the researchers have found.

"Observing someone who is stressed--especially a co-worker or family member--can have an immediate effect upon our own nervous systems," Shawn Achor, the author of The Happiness Advantage and Before Happiness, and Michelle Gielan, the author of Broadcasting Happinesswrite in Harvard Business Review.

Achor and Gielan write about another group of researchers who found that 40 percent of people get stressed when their romantic partner is stressed. And nearly a quarter of participants in that study experienced stress symptoms after watching a "stressful event" on TV while sitting next to strangers.

"When your taxi driver honks angrily, you can carry his anxiety all the way to work. When a boss hurriedly stalks into a room, you can pick up her stress as you try to present your ideas. Even bankers on trading floors separated by glass walls can pick up the panic of a person across the room working in a separate market just by seeing their nonverbals," the authors say.

Heidi Hanna, a fellow at the American Institute of Stress and author of Stressaholic, explains that the bio-mechanical rhythms--heart rate and breathing--can transmit stress to other people. "Most people have experienced spending time with someone who triggers a stress response just by walking in the door," she tells HBR.

So how do you innoculate yourself against stress? Achor and Gielan break down three ways you can avoid catching the bug.

1. No-stress zone

As a leader, you can use knowledge about how stress spreads to create a healthy environment in the office. In Before Happiness, Achor writes about how companies like the Ritz Carlton and Oschner Health Systems created "no venting zones" in their offices to prevent negative people from infecting the entire company. That may sound pretty odd, but as you've no doubt experienced, one person stomping around and complaining can ruin everyone's mood. 

2. Hack your brain's response

You can reprogram your brain's response to stress. Fighting stress can result in frustration, but if you change your behavior around the emotion, you can eventually change your body's reaction. Achor, along with Alia Crum of Stanford’s Mind & Body Lab and Peter Salovey of the Yale Center for Emotional Intelligence, did research on this method at investment banking firm UBS. "We found that if you create a positive mindset about stress and stop fighting it, you experience a 23 percent drop in the negative effects of stress," Achor and Gielan write. 

3. Self-esteem booster

Just like how antibodies fight disease in our body, positivity and self-esteem can act as antibodies towards stress. "If you are finding yourself being impacted by others' moods, stop and remind yourself how things are going well and that you can handle anything that comes your way," the authors write. "Exercise is one of the best ways to build self-esteem, because your brain records a victory every time you exercise, via endorphins."