This story appears in the September 2017 issue of National Geographic magazine.

As U.S. surgeon general from 2014 until spring 2017, Vivek Murthy, 40, extended his office’s public health advocacy to matters such as reliable transportation, safe neighborhoods, and affordable housing. Now, he continues to push to reduce stigmas around mental illness and to promote emotional well-being and healthy habits. He spoke to National Geographic.

You say emotional well-being is just as important as eating a healthy diet and staying active. Why?

When I began my tenure as surgeon general, I did not intend to focus on emotional well-being. But it became a priority after I traveled the country listening to people in small towns and big cities. What I sensed was that people were experiencing a high degree of emotional pain. I think of emotional well-being as a resource within each of us that allows us to do more and to perform better. That doesn’t mean just the absence of mental illness. It’s the presence of positive emotions that allows us to be resilient in the face of adversity.

How do we fix that?

The first thing is that we need to change how we think about emotions. Emotions are a source of power, and that’s what science tells us. But many people I encounter have been led to think of emotions as a source of weakness. The second thing we have to do is cultivate emotional well-being. There are tools, and they’re relatively simple. They include sleep, physical activity, contemplative practices like gratitude and meditation, and social connection as well.

In today’s news you can see a lot of stress, people burned out. What does that tell you as a physician?

I am deeply concerned about the level of stress that our country is experiencing. I think it’s preventing us from achieving our full potential. I have long believed that there are fundamentally two forces or emotions that drive our decisions— love and fear. Love has its many manifestations: compassion, gratitude, kindness, and joy. Fear often manifests in cynicism, anger, jealousy, and anxiety. I worry that many of our communities are being driven by fear. It’s partly because of the things we read about in the news that give us pause about the state of the world. And it’s also because we haven’t really prioritized cultivating positive emotions that emanate from love.