Which disease involves the immune system attacking joints, leading to pain and stiffness?

Rheumatoid arthritis is an autoimmune disease where the immune system mistakenly attacks the synovium, the lining of the joints. This immune response triggers inflammation, which results in symptoms such as pain, swelling, and stiffness in the affected joints. Over time, the inflammation can damage the cartilage and bone within the joint, leading to decreased mobility and function.

Understanding the nature of this condition is crucial, as it differentiates rheumatoid arthritis from other forms of arthritis, such as osteoarthritis, which is primarily due to wear and tear rather than an autoimmune response. Lupus also involves immune system dysfunction but affects multiple systems in the body rather than being localized primarily to the joints. Multiple sclerosis is a neurodegenerative disorder that impacts the central nervous system rather than presenting symptoms specifically linked to joint involvement. Thus, the identification of rheumatoid arthritis is essential for proper diagnosis and treatment within the context of musculoskeletal disorders.