The report, from the Centers for Disease Control and Prevention (CDC), found that nearly 70 million people said they had joint woes last year. Experts had believed the number was closer to 43 million, and that included not only adults but children, too.

"This new national estimate is much larger than before," says Dr. Chad Helmick, a CDC joint expert and a co-author of the study. "There are a lot of people out there who are telling us they have chronic joint symptoms" or the full-blown inflammatory disease.

Based on the survey, about 22 million people have been diagnosed with arthritis; 21 million have recurrent joint symptoms, such as pain and stiffness; and more than 26 million have both chronic symptoms and a diagnosis of arthritis.

Arthritis is the nation's leading source of disability, causing substantial limitations in between 7 million and 8 million people. The latest study doesn't change that number, Helmick says. But, he adds, people with joint symptoms shouldn't ignore the pain and stiffness, since these symptoms can be treated. Many drug therapies are available for arthritis, but lifestyle changes such as exercise and losing weight also can improve the condition.

"The numbers are staggering," says Tino Mantella, president and chief executive officer of the Arthritis Foundation. "We need more people to take action" and seek treatment for their joint troubles. "They are compromising their lifestyle and in many cases unnecessarily."

The survey included more than 212,000 men and women in all 50 states and Washington, D.C., who were asked if they'd ever been diagnosed with arthritis or if they'd had chronic joint symptoms during the past 12 months. To meet the definition of chronic symptoms, participants had to have stiffness, pain, or swelling around a joint for most of the days of the month.

As expected, women were more likely than men to have joint problems, and the incidence of these ailments rose with age. Whites and blacks reported them more often than Hispanics and other ethnic groups. Being overweight, not completing high school, and being physically inactive increased the chances of arthritis and chronic joint symptoms.

The national average for the prevalence of arthritis was just above 33 percent, but the numbers varied widely throughout the country. West Virginia had the highest proportion, at 42.6 percent; Hawaii had the lowest, at 17.8 percent.

Helmick says the epidemic of obesity tracks a recent rise in joint problems. The aging population is also affecting the demographics of the disease, since arthritis is more common in the elderly. As Americans live and work longer, more will be struggling on the job with the debilitating affects of arthritis, he adds.

What To Do

To find out more about arthritis and what to do about it, try the Arthritis Foundation or the Centers for Disease Control and Prevention.