Poor social skills may be harmful to health

While the negative effects of stress on the body have been known for a long time, loneliness is a more recently recognized health risk factor.

"We started realizing about 15 years ago that loneliness is actually a pretty serious risk for health problems. It's as serious of a risk as smoking, obesity or eating a high-fat diet with lack of exercise," Segrin said.

Segrin likens the experience of loneliness to the way people feel when they're in a hurry to get out the door and can't find their keys -- except the feeling never truly goes away.

"When we lose our keys, 99 percent of the time we find them, the stress goes away, we get in the car and it's over," he said. "Lonely people experience that same sort of frantic search -- in this case, not for car keys but for meaningful relationships -- and they don't have the ability to escape from that stress. They're not finding what they're looking for, and that stress of frantically searching takes a toll on them."