The word 膀胱炎 is formed by combining the characters 膀胱 (pángguāng), which means "bladder", and 炎 (yán), which means "inflammation". The character 炎 serves as the core component indicating a medical condition of inflammation, while 膀胱 specifies the anatomical location affected. Thus, the compound directly denotes "bladder inflammation" or cystitis.