SALEM — Nearly a third of Oregon households consist of someone living alone.

That’s more than a half-million people with no one else in their household. It is a record high, according to the most recent data from the U.S. Census Bureau and the Oregon Office of Economic Analysis.

And the share of Oregon residents who live alone is up by about 50% this century.

Oregon’s shift mirrors national trends, according to Josh Lehner, a state economist who wrote an analysis of the state’s single-person households earlier this year.

Relatively few adults live alone in their 20s and 30s, Lehner noted. People often have roommates to help cover their housing costs, then form couples as they age. Many start families.

The number of people living alone is much higher among seniors. That’s partly because some have divorced, Lehner wrote, and partly because some of their spouses have died. The rate of Oregonians living alone rises sharply after age 75, and nearly all that increase is among women, who tend to live longer.

The number of Americans living alone has more than doubled since 1960, when just 1 in 8 households consisted of someone living by themselves, according to a federal report last year.

Many live alone by choice and are perfectly happy on their own. But the report by the U.S. Surgeon General found that living alone is one of several risk factors for rising loneliness and social isolation.

The report urges all levels of society to be more proactive in encouraging connections among people to fight feelings of loneliness, and suggests each person should make more of an effort to connect with friends and neighbors.

“Our individual relationships are an untapped resource — a source of healing hiding in plain sight,” wrote Surgeon General Vivek Murthy. “They help us live healthier, more productive and more fulfilled lives.”