<aside>

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that primarily affects synovial joints, leading to progressive joint destruction, deformities, and functional disability.

</aside>

https://www.youtube.com/watch?v=EB5zxdAQGzU

https://youtu.be/rhwe0fb2Um4

https://www.youtube.com/watch?v=ld8PhyAHov8

https://www.youtube.com/watch?v=Lk9pGGKPoKw

https://www.youtube.com/watch?v=4GMOaXE0ClE

https://www.youtube.com/watch?v=aCbgps77scM

https://www.youtube.com/watch?v=u_A8kOBP-K8

• It is symmetrical and polyarticular, most commonly involving the small joints of the hands and feet.

Epidemiology

• Prevalence: ~1% worldwide
• Female-to-male ratio: 3:1
• Peak onset: 30–50 years
• Genetic association: HLA-DR4, HLA-DR1

Pathophysiology

• Autoimmune-mediated chronic synovitis → proliferation of pannus (granulation tissue)
• Pannus invades cartilage and bone, causing:
  • Erosions
  • Joint space narrowing
  • Deformity
• Extra-articular involvement: lungs, eyes, heart, vessels