Rheumatoid arthritis is a chronic inflammatory disease that causes pain, stiffness, and swelling in the joints. It occurs when the immune system mistakenly attacks the joints, causing the synovial membrane to become inflamed. Over time, this can cause cartilage and bone damage and limit function. Treatment focuses on reducing inflammation, managing symptoms, and preventing further joint damage through medications, surgery, and lifestyle changes. While there is no cure, proper treatment can help improve quality of life by reducing pain and disability.