When the left side of the throat is swollen, first of all, it is necessary to exclude that it is caused by trauma. If it is not caused by trauma, it is mainly due to acute inflammation with its clinical symptoms such as redness, swelling, heat and pain. Acute pharyngitis, acute tonsillitis, purulent tonsillitis, peri-tonsillar abscess, oral ulcer, acute epiglottitis and maxillofacial interstitial infection, as well as gingivitis, periodontitis and endodontitis in dentistry can indirectly stimulate the mucosa of the pharyngeal cavity and cause clinical symptoms such as swelling and pain. First of all, we can perform a preliminary diagnosis of the location of the swelling by fiberoptic rhinolaryngoscopy, and then treat the symptoms.