Rheumatoid arthritis is a chronic inflammatory disease of the joints and the surrounding tissues. It is an autoimmune disease. The exact cause of rheumatoid arthritis is unknown. Infection, genes and hormonal changes may be linked to the disease. A recent study which took into account abdominal obesity, body fat percentage and body mass index (BMI), shows that there is an association between overweight, obesity and the risk of developing RA in women.