Which symptom is a common result of rheumatoid arthritis?

Swelling of the joints is a hallmark symptom of rheumatoid arthritis, which is an autoimmune condition characterized by inflammation of the synovial tissue surrounding the joints. This inflammation leads to increased fluid accumulation in the joints, which manifests as swelling, pain, and stiffness, particularly in the morning or after periods of inactivity. This symptom is a direct result of the body's immune response attacking the joint tissues. The other options do not reflect common symptoms associated with rheumatoid arthritis, as improved joint function, decreased fatigue, and increased energy are typically not experienced by individuals with this condition. In fact, rheumatoid arthritis often leads to the opposite effects, including reduced joint function, increased fatigue, and lower energy levels due to pain and systemic inflammation.