One of the most common problems in our world today, touching millions of people on every continent, is persistent, pervasive loneliness: 1 in 4 people in the world say they're lonely.

• That's according to new research from Gallup.

The big picture: The pandemic spotlighted loneliness around the world — and the problem isn't going away. This year, Surgeon General Vivek Murthy declared loneliness an epidemic in the U.S.

By the numbers: 24% of adults said they feel very or fairly lonely, according to a Gallup survey of people around the world.

• 27% said they felt a little lonely, and just 49% said they didn’t experience loneliness at all.

Why it matters: Loneliness harms our mental and physical health — increasing risk of heart disease, dementia and stroke.

• One widely cited NIH analysis equates the health effects of persistent loneliness to smoking 15 cigarettes a day.

Zoom in: Global loneliness is hitting young people harder than older folks, Gallup found.

• While 27% of those between the ages of 18 and 29 said they felt very or fairly lonely, just 17% of those over 65 felt the same way.
• Younger adults are more likely to be single and childless, which can contribute to loneliness.

First look: Surgeon General Murthy will announce a college tour tomorrow. He'll travel around the country to speak to students — who have some of the highest rates of loneliness in America — about social connection.

• The first two stops are at Duke tomorrow and UVA on Thursday.
• The tour continues through the fall and includes stops at the University of Washington, UT Austin and Arizona State University.
• "Just like exercise and nutrition, our relationships with one another are fundamental components of our overall health and well-being," Murthy said.

The bottom line: Send the text, make the call, start the conversation — we could all use the connection.

• Go deeper: Surgeon General's deep dive on loneliness

Finish Liner Kayla K. grabbed this pic on a walk through her neighborhood.

• "I am so grateful to live where I do in Boulder, Colo., and every day when I walk the trails near my home, I feel so lucky to have the green space we do here. It's really the center point to our lives."