Several other diseases have symptoms similar to osteoarthritis (OA). They include:
- Rheumatoid arthritis (RA), an autoimmune disease that can cause pain in the joints. RA occurs when the immune system attacks the joints and muscles causing joint pain and stiffness.
- Lupus, an autoimmune disease like RA, that causes inflammation in the joints, as well as in the tendons, skin and other connective tissues.
- Gout, which occurs when uric acid crystals build up in the joints, and causes joint inflammation, pain and tenderness.
- Bursitis, which occurs when the bursa (a fluid-filled sac) in the joints is irritated, can also cause pain.
- Tendinitis, which occurs in the tendons from overuse or strenuous exercise, can cause pain, swelling and decreased motion in the affected joints.
A doctor can often distinguish between OA and other conditions using a physical exam and x-rays.