肩周炎 (jiān zhōu yán) is a common medical term in Chinese referring to 'frozen shoulder' — a painful condition characterized by stiffness and limited range of motion in the shoulder joint, often due to inflammation and thickening of the surrounding capsule. Literally, 肩 means 'shoulder', 周 means 'around' or 'peripheral', and 炎 means 'inflammation'. Together, the term describes inflammation around the shoulder joint — precisely capturing its clinical nature.

This condition typically affects adults aged 40–60 and may develop gradually over months. In Chinese healthcare contexts, 肩周炎 is widely used by doctors, physical therapists, and patients alike. It appears frequently in medical reports, health education materials, and conversations about chronic musculoskeletal issues. Unlike colloquial terms like 'stiff shoulder', 肩周炎 carries formal, clinical weight and is rarely used metaphorically.