What symptom is indicative of rheumatoid arthritis in a patient?

Swollen joints with limited motion is a classic symptom of rheumatoid arthritis (RA) and serves as a key indicator of the condition. RA is characterized by chronic inflammation of the joints, which leads to synovitis (inflammation of the synovial membrane) and results in swelling. This swelling is typically accompanied by pain and a significant reduction in the range of motion of the affected joints due to both inflammation and potential structural changes over time.

In rheumatoid arthritis, multiple joints may be affected symmetrically, which is distinct from other forms of arthritis where swelling might be localized to one joint. Patients often experience difficulties in performing everyday activities due to this reduced motion and pain, making it a critical symptom to identify.

Other symptoms listed, such as localized pain without swelling, weakness and fatigue, and morning stiffness, can also be associated with rheumatoid arthritis but are less definitive on their own. For example, morning stiffness is common but not exclusive to RA, as it can be seen in many other types of musculoskeletal conditions. Similarly, weakness and fatigue are systemic symptoms that can relate to various health issues and do not specifically point to rheumatoid arthritis without the context of joint symptoms.