Rheumatoid arthritis (RA) is a chronic inflammatory disease, which affects 1% of the world's population. Patients with RA not only have a progressive and debilitating disease and severe functional impairment, but can also experience a reduced life expectancy due to frequent involvement of the major organ systems. This new edition of Rheumatoid Arthritis charts the profound changes in research and patient management that have taken place over the last 5 years. Developments in molecular biology have dramatically increased insight into the inflammatory and destructive pathways of this complex disease. Over half a million patients have been successfully treated with biologic therapy and advances in imaging techniques have allowed increasingly early detection of disease onset. Rheumatoid factor is no longer the unchallenged gold standard autoantibody but has competition from the anti-citrulline antibodies. Environmental factors influencing both susceptibility and progression have been sought, and smoking has emerged as a powerful factor. Steady progress in genetics is finally being made and one day it may be possible to predict RA before onset of symptomatic disease.It is against this backdrop of dynamic developments that the new edition of Rheumatoid Arthritis publishes.