What autoimmune condition is characterized by joint inflammation and stiffness?

Rheumatoid arthritis is an autoimmune condition that prominently features joint inflammation and stiffness. It occurs when the immune system mistakenly attacks the synovium, which is the lining of the membranes that surround the joints. This leads to inflammation, swelling, and pain in the affected joints. Morning stiffness lasting more than an hour and symmetrical joint involvement are classic signs associated with rheumatoid arthritis, distinguishing it from other types of arthritis.

In contrast, osteoarthritis is primarily a degenerative joint disease characterized by the wear and tear of cartilage rather than an autoimmune process. Lupus, while it can affect the joints, is a systemic autoimmune illness that presents with various symptoms, including skin rashes and organ involvement beyond just joint issues. Fibromyalgia is a chronic pain condition that includes widespread musculoskeletal pain, along with fatigue and tenderness, but it does not primarily involve inflammatory joint processes like those seen in rheumatoid arthritis. Thus, each of these conditions presents differently, positioning rheumatoid arthritis as the answer that directly aligns with the specified characteristics of joint inflammation and stiffness.