Could that joint pain be rheumatoid arthritis?

How to distinguish the symptoms from other conditions, and what to do about treatment.

Image: © PositiveFocus/Thinkstock

When your joints ache, you may chalk it up to an old injury or to osteoarthritis — the wearing away of cartilage that's common in older age. But for two million people in the United States, aching joints are caused by rheumatoid arthritis (RA) — when the immune system mistakenly attacks the tissues lining the joints.

"People commonly assume RA pain is due to aging, overuse, or even the flu," says Dr. Robert Shmerling, a rheumatologist at Harvard-affiliated Beth Israel Deaconess Medical Center, and medical editor of the Harvard Special Health Report Rheumatoid Arthritis (health.harvard.edu/RA).