Rheumatoid arthritis is a chronic inflammatory rheumatic disease with clinical and biological signs of inflammation, responsible for bone and cartilage defects. These latter are responsible for irreversible functional impairment. Because of the lack of effective therapy of the disease, there is a need for clinical, biological and radiological outcome variables to assess the symptomatic and structural severity of the disease. Different consensual meetings of the international rheumatological community dramatically facilitated uniformization of the medical language in this field by providing simple accurate tools to be used in daily practice.