**M25.5 — Pain in joint** is used when joint pain (arthralgia) is documented without identifying inflammation, injury, or a specific arthropathy. Sub-codes specify location (M25.51 shoulder, M25.56 knee, M25.57 ankle/foot, etc.).
When inflammation is present, codes shift to M00-M19 (arthropathies). Cartilage or ligament injuries get S-codes.
Belongs to **Chapter M** — Diseases of the musculoskeletal system.
