Can rheumatoid arthritis be mistaken for osteoarthritis?

Donna Hill Howes, RN
Family Medicine
Osteoarthritis and rheumatoid arthritis can be mistaken for each other because both are characterized by swelling and inflammation. However, rheumatoid arthritis is different because in this condition, the body's immune system attacks the joints. This can happen suddenly and cause severe inflammation. On the other hand, osteoarthritis is caused by a breakdown of joint cartilage and tends to develop over time.
Natalie E. Azar, MD
Internal Medicine
Rheumatoid arthritis and osteoarthritis share similar symptoms, but RA symptoms tend to be more severe and for longer periods. Watch rheumatologist Natalie Azar, MD, discuss how these two conditions are different and how doctors distinguish them.

While both rheumatoid arthritis (RA) and osteoarthritis (OA) affect our joints, they cause unique problems allow us to diagnose them separately. RA typically causes morning stiffness that lasts greater than an hour, affects the small joints of the hands and feet symmetrically, and can cause whole body symptoms such as fatigue. OA usually affects the large joints asymmetrically with stiffness increasing as the day goes on or with prolonged rest. Rarely does OA cause systemic or whole body symptoms. Also RA can occur at any age while OA is more commonly seen in older individuals after years of joint breakdown.

Because both rheumatoid arthritis and osteoarthritis cause joint pain and stiffness, the two conditions are sometimes mistaken for one another. However, rheumatoid arthritis also tends to affect the entire body, causing achy muscles, fatigue, weight loss and flu-like symptoms. Also, rheumatoid arthritis usually affects the same joint on both sides of the body such as both wrists or both knees.

Rheumatoid arthritis is an autoimmune disease in which the immune system mistakenly attacks healthy cells and tissues. Osteoarthritis is a painful joint disease caused by age-related wear and tear, injury or, in rare cases, genetic illnesses.

No single test can diagnose osteoarthritis. Most doctors use several methods to diagnose the disease and rule out other problems. These methods include:
  • Taking a medical history
  • Giving a physical exam
  • X-raying painful areas
  • Giving blood tests or examine the fluid in the joints
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Rheumatoid arthritis (RA) might be initially mistaken for osteoarthritis (OA), but the symptoms of RA are different from those of OA. RA usually brings severe pain, swelling and an extremely limited range of motion. The affected joints are often swollen, red and warm to the touch. RA is also symmetrical, which means that if you have an affected joint on one side of your body, the same joint on the other side is likely to be affected too. RA causes fatigue, loss of appetite and sometimes a low fever. Perhaps the biggest difference between RA and OA is that RA tends to come in flare-ups -- you have an attack of bad pain and inflammation that may then go away for a long time. But with OA, you don't get flare-ups or periods of remission.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.