Many in Middle Age Have Arthritis—They Just Don’t Know It

It may start as a stiff knee, soreness in the hips, or swelling in the fingers that makes it hard to hold a coffee cup.

The joint disease arthritis is on the rise in the U.S., driven largely by the aging of the baby-boom generation and the obesity epidemic. But while the Centers for Disease Control and Prevention estimates 54 million adults have been told by a doctor they have the condition, new research suggests a much higher prevalence—especially in the 45-64 age group—totaling more than 91 million adults.