Medical term for a chronic autoimmune disease causing joint inflammation and deformity.
Rheumatoid arthritis is caused by an abnormality in the immune system.
Synonymous medical term; 関節リウマチ is more common in clinical settings, while リウマチ性関節炎 is a direct translation of the English term.
From リウマチ (rheumatic) + 性 (-like, -type) + 関節炎 (arthritis). A direct calque of the English medical term 'rheumatoid arthritis'.