Pharyngitis (yān yán) is a medical term referring to inflammation of the pharynx—the part of the throat located between the mouth and the larynx. The character 咽 (yān) means 'pharynx' or 'throat,' while 炎 (yán) means 'inflammation' or 'swelling caused by infection or irritation.' Together, they form a compound noun used exclusively in clinical and health-related contexts.

This word appears frequently in doctor-patient communication, medical reports, prescriptions, and health education materials. It is not used in casual daily speech—people typically say 喉咙痛 (hóu lóng tòng, 'sore throat') instead when describing symptoms informally. Pharyngitis may be caused by viruses, bacteria, or environmental irritants, and is often accompanied by soreness, difficulty swallowing, or mild fever.