When your doctor told you she suspected you had rheumatoid arthritis, you probably thought, “Arthritis – that’s a disease old people get.”

You’re thinking of osteoarthritis, the most common kind of arthritis, a disease in which cartilage in the joints breaks down. It does become more prevalent with age.

Though RA affects the joints, it’s a disease of the immune system, which normally protects us from infection by attacking viruses and bacteria. For reasons no one fully understands, RA causes the immune system to go awry and mistakenly attack healthy cells such as the synovium, a thin membrane that lines the joints. As a result of the attack, fluid builds up in the joints, causing pain and inflammation. Over time this can wear away the cartilage and erode bone, causing a lack of function and mobility. In most people, the inflammation usually becomes systemic, affecting organs such as the skin, heart and lungs.

RA most commonly affects the joints of the hands, feet, wrists, elbows, knees and ankles. Joint involvement is usually symmetrical, meaning if one joint is affected the same joint on the opposite side of the body is involved as well.

While there’s no cure for this chronic disease, its symptoms often come and go. Periods of mild disease activity may be punctuated by flares – bouts of more intense activity and symptoms. In some cases, with appropriate treatment, the disease goes into remission.

If you’ve just been diagnosed with RA, you should know you’re not alone – the disease affects an estimated 1.5 million Americans. Three times more women are affected than men. The usual age for adult onset is between 40 and 60 years, but it can begin at any age, even in childhood.

Diagnosing RA Can Be Tricky

Because no single laboratory test instantly confirms a diagnosis of RA, doctors must employ a variety of methods to make the call.
If your doctor thinks you might have RA, the first order of business will be to take your medical history. This helps him gather specific information about your symptoms that might point to RA: Do you have pain in several joints? Do the same joints hurt on each side of your body? Do you experience stiffness in the morning? Are you often fatigued?

Doctors also may use a Health Assessment Questionnaire or an Arthritis Impact Measurement Scale, sets of questions and answers that gauge your pain level and your outlook on life. Then comes a physical exam. The doctor will look for swelling, warmth, tenderness and limited motion in joints, or nodules under the skin. He might ask you to perform certain tasks to see how well you function.