Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease driven by T-cell and B-cell dysregulation that causes symmetric, destructive polyarthritis — primarily targeting the synovial lining of diarthrodial joints. Unlike osteoarthritis, RA produces pannus formation: an invasive proliferating synovial tissue that erodes cartilage, subchondral bone, and periarticular structures. Missed or delayed diagnosis leads to irreversible joint deformity, functional disability, and accelerated cardiovascular mortality (RA patients have a 1.5–2× higher MI risk than the general population). Top 3 nursing priorities: 1. Pain management and preservation of joint function through positioning, splinting, and timing of activity (mornings are worst — peak stiffness lasts >60 minutes). 2. Monitoring for drug toxicity — methotrexate-induced hepatotoxicity and pulmonary toxicity are the leading causes of serious adverse events in treated RA. 3. Surveillance for extra-articular manifestations: rheumatoid nodules, pericarditis, pleuritis, and vasculitis can develop even when joint disease is controlled. Common NCLEX trap: Students confuse RA morning stiffness (>1 hour, improves with activity) with osteoarthritis stiffness (<30 minutes, worsens with activity). RA is symmetric — unilateral joint involvement strongly suggests another diagnosis. Also: biologic DMARDs (e.g.,...