Stress and worry can be a sign that your life has a meaning.

As a health psychologist, Kelly McGonigal, Ph.D., aims to help people live happier, healthier lives.

So it makes sense that she's spent the better part of her career encouraging them to avoid stress and its damaging effects.

Yet when she spoke at the 99U conference in New York on Thursday, McGonigal said her approach to stress management has changed fundamentally in recent years.

Now, she says, she understands that stress isn't inherently harmful. A growing body of research offers two possible reasons.

First, stress and worry can be a sign that your life has meaning. Being stressed generally means you're engaged in something that really matters to you — whether that's interviewing for a dream job or taking care of your kid.

Second, simply being aware of the benefits of stress can help you cope with it.

"All too often, in moments of stress we view that stress as a signal that we are inadequate or our lives are toxic," she said. "But how you think about stress plays a powerful role in how it affects your well-being."

For example, say you're one of the many Americans who (understandably) perceive stress as negative and try to avoid it all costs. Chances are that when you do experience a stressful situation — like that job interview — your body will release higher levels of stress hormones like cortisol, which can have damaging effects on your immune system and overall health.

But let's say you go into that interview understanding and even embracing the potential advantages of stress. Studies indicate that not only will you have a healthier physiological response; you're also more likely to find meaning in your struggle and learn from it.

McGonigal's current challenge is not helping people reduce the amount of stress in their lives — but persuading them to stop resisting it.

Ultimately, she said, stress is "not a signal that there's something wrong with your life." On the contrary, being stressed means you're fully invested in whatever you're doing.

As for the next time you show up sweaty-palmed and shaky-legged to a job interview? Telling yourself to calm down probably won't help. Instead, try thinking about it this way: "Something I care about is at stake." Those nerves will subside before you know it.