The key hand features of rheumatoid arthritis primarily manifest as symmetrical joint swelling and pain in both hands in the early stages. These swollen and painful joints include both wrist joints, bilateral metacarpophalangeal joints, and bilateral proximal interphalangeal joints. Rheumatoid arthritis rarely affects the distal interphalangeal joints of the hands. In the later stages of rheumatoid arthritis, due to the destruction of the hand joints by synovitis, some patients may develop deformities in the hand joints, commonly including ulnar deviation, swan neck deformities, or boutonniere deformities. Some patients may experience significant stiffness leading to limited mobility of the hand joints.