Rheumatoid arthritis (RA) is an autoimmune disorder that primarily affects the joints, causing chronic inflammation, pain, swelling, and stiffness. Unlike osteoarthritis, which is caused by wear and tear on the joints, RA occurs when the immune system mistakenly attacks the body's own tissues, specifically the synovium, the lining of the membranes that surround the joints

The exact cause of RA is unknown, but it is believed to involve a combination of genetic, environmental, and hormonal factors. Certain genes may make individuals more susceptible to developing RA, and environmental triggers such as infections or smoking may play a role in triggering the autoimmune response

Diagnosis of RA typically involves a combination of medical history, physical examination, blood tests, and imaging studies. Blood tests may include rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies, which are often elevated in individuals with RA. Imaging tests such as X-rays or ultrasound may be used to assess joint damage and inflammation