Since rheumatoid arthritis is a systemic disease, its inflammation can affect organs and areas of the body other than the joints. Examples of other areas that may be affected include the following:
- Sjögren's syndrome is the result of inflammation of the glands of the eyes and mouth and causes dryness of these areas.
- Rheumatoid inflammation of the lung lining (pleuritis) causes chest pain with deep breathing or coughing.
- Tissue inflammation surrounding the heart, called pericarditis, can cause chest pain that typically changes in intensity when lying down or leaning forward.
- Rheumatoid disease can reduce the number of red blood cells (anemia) and white blood cells.
- Decreased white cells can be associated with an enlarged spleen (Felty's syndrome) and can increase the risk of infections.
- Firm lumps under the skin (rheumatoid nodules) can occur around the elbows and fingers where there is frequent pressure.
- A rare and serious complication is blood-vessel inflammation (vasculitis). Vasculitis can impair blood supply to tissues and lead to tissue death. This is most often initially visible as tiny black areas around the nail beds or as leg ulcers.