While rheumatoid arthritis may begin at any age, it most commonly affects people between the ages of 20 and 40. The cause of rheumatoid arthritis is not known. Some researchers say it is caused by infection. Heredity is definitely a factor. There is some agreement among researchers that the body’s immune system is somehow involved in the development of rheumatoid arthritis.

Researchers believe that there is a foreign substance that may contribute to the development of rheumatoid arthritis, but they haven’t isolated it yet. Inflammation induced by this foreign substance is thought to be responsible for the joint pain, swelling, and destruction so commonly seen in patients with this disease.

How is Rheumatoid Arthritis Diagnosed?

If this disease is suspected, your physician will find several laboratory tests helpful in addition to a complete physical examination, a health history, and X-rays. A test called the erythrocyte sedimentation rate (ESR) will indicate the presence of any inflammation in your body. You need only have a small blood sample drawn; then the depth that the red blood cells sink in a tube in one hour is recorded. Another test done with your blood sample helps determine the presence of rheumatoid factor, an abnormal antibody present in most people who have rheumatoid arthritis. In normal conditions the presence of abnormal antibody is nil. While rheumatoid factor may be present in people without rheumatoid arthritis, if symptoms of arthritis are present, the additional information regarding rheumatoid factor will be a useful diagnostic tool for your physician.