Rheumatoid arthritis is a result of misdirected inflammation. When inflammation occurs, chemicals from the body's white blood cells are released into the blood or affected tissues to protect your body from foreign substances. This release of chemicals increases the blood flow to the area of injury or infection, and may result in redness and warmth. Some of the chemicals cause a leak of fluid into the tissues, resulting in swelling. This protective process may stimulate nerves and cause pain. Follow the links below to find WebMD's comprehensive coverage about rheumatoid arthritis inflammation, how to treat it, and much more.