Rheumatoid arthritis, or RA, is an autoimmune and inflammatory disease, which means that your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) in the affected parts of the body.
RA mainly attacks the joints, usually many joints at once. RA commonly affects joints in the hands, wrists, and knees. In a joint with RA, the lining of the joint becomes inflamed, causing damage to joint tissue. This tissue damage can cause long-lasting or chronic pain, unsteadiness (lack of balance), and deformity (misshapenness).
RA can also affect other tissues throughout the body and cause problems in organs such as the lungs, heart, and eyes.
RA is diagnosed by reviewing symptoms, conducting a physical examination, and doing X-rays and lab tests. It’s best to diagnose RA early within 6 months of the onset of symptoms so that people with the disease can begin treatment to slow or stop disease progression (for example, damage to joints). Diagnosis and effective treatments, particularly treatment to suppress or control inflammation, can help reduce the damaging effects of RA.