Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks flexible (synovial) joints. The process involves an inflammatory response of the capsule around the joints (synovium) secondary to swelling (hyperplasia) of synovial cells, excess synovial fluid, and the development of fibrous tissue (pannus) in the synovium. The pathology of the disease process often leads to the destruction of articular cartilage and ankylosis (fusion) of the joints. Rheumatoid arthritis can also produce diffuse inflammation in the lungs, membrane around the heart (pericardium), the membranes of the lung (pleura), and white of the eye (sclera), and also nodular lesions, most common in subcutaneous tissue. Although the cause of rheumatoid arthritis is unknown, autoimmunity plays a pivotal role in both its chronicity and progression, and RA is considered a systemic autoimmune disease.
About 1% of the world's population is afflicted by rheumatoid arthritis, women three times more often than men. Onset is most frequent between the ages of 40 and 50, but people of any age can be affected. In addition, individuals with the HLA-DR1 or HLA-DR4 serotypes have an increased risk for developing the disorder. It can be a disabling and painful condition, which can lead to substantial loss of functioning and mobility if not adequately treated. It is a clinical diagnosis made on the basis of symptoms, physical exam, radiographs (X-rays) and labs, although the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) publish classification criteria for the purpose of research. Diagnosis and long-term management are typically performed by a rheumatologist, an expert in joint, muscle and bone diseases.
Various treatments are available. Non-pharmacological treatment includes physical therapy, orthoses, occupational therapy and nutritional therapy but these do not stop the progression of joint destruction. Analgesia (painkillers) and anti-inflammatory drugs, including steroids, are used to suppress the symptoms, while disease-modifying antirheumatic drugs (DMARDs) are required to inhibit or halt the underlying immune process and prevent long-term damage. In recent times, the newer group of biologics has increased treatment options. Clinical trials have shown that consumption of fish oil reduces the number of swollen joints for people with rheumatoid arthritis, provides a beneficial anti-inflammatory effect, and provides a protective effect for occlusive cardiovascular disease, for which people with RA are at risk.
The name is based on the term "rheumatic fever", an illness which includes joint pain and is derived from the Greek word peuva-rheuma (nom.), pevuatoc-rheumatos (gen.) ("flow, current"). The suffix -oid ("resembling") gives the translation as joint inflammation that resembles rheumatic fever. The first recognized description of rheumatoid arthritis was made in 1800 by Dr. Augustin Jacob Landré-Beauvais (1772–1840) of Paris.