ATLANTA (AP) — Arthritis and other chronic joint problems are far more widespread than estimated just five years ago, affecting one in three U.S. adults, or 69.9 million people in all, the government said Thursday in the first comprehensive survey of the disease.

Health officials and advocates said the numbers — and related health care costs — are expected to continue to rise as the baby boom generation reaches old age.

The survey shocked even advocates for arthritis sufferers.

“We just think that’s alarming in terms of the number,” said Tino Mantella, president of the Arthritis Foundation.

The numbers were 63 percent higher than a 1997 estimate that said about one in five U.S. adults, or nearly 43 million in all, had arthritis and other chronic joint problems.

The new survey by the Centers for Disease Control and Prevention reflects, in part, a real increase in arthritis, connected to the aging of the baby boomers. But it also reflects a more thorough survey, the CDC said.

Previous estimates were much lower because many people do not tell doctors about their joint pain, and others do not consider their aches and pains to be arthritis, officials said. The latest survey employed more penetrating questions.

A total of 212,000 people from all 50 states were interviewed by telephone and asked if, in the previous year, they had pain, stiffness or swelling around a joint for at least a month. About a third of those with arthritis-like symptoms said they had not consulted a doctor about their symptoms.

“There are many people with chronic joint symptoms who don’t see a doctor,” said Dr. Chad Helmick of the CDC’s arthritis program. The latest survey “is a better way of capturing people who have always been out there with arthritis or different symptoms.”

The arthritis level ranged from 17.8 percent of adults in Hawaii to 42.6 percent of adults in West Virginia. States in the central and northwestern parts of the country had the highest rates.

Last year, arthritis patients cost the country about $80 billion in medical care costs and lost work, health officials said.

People can reduce their risk of arthritis through exercise, weight management and a healthy diet.

“The public has very little understanding about arthritis,” said Dr. John Klippel, medical director for the Arthritis Foundation. “Many people associate arthritis with the process of aging, they assume aches and pains are an inevitable part of aging when in fact it is not a natural part of aging.”

The survey confirmed previous studies that indicated arthritis tends to rise with age and that it is more common in women. In addition, arthritis is more common in those who are overweight or physically inactive.