Gum swelling and pain in the left wisdom tooth place may be caused by wisdom tooth pericoronitis, the treatment is local rinsing, medication, incision and drainage, and after the inflammation subsides, the gingival flap is removed or the wisdom tooth is extracted, the details are as follows. 1. Local rinsing: Use 0.1% chlorhexidine solution to rinse the gingival pocket repeatedly until the overflow liquid becomes clear, and then put a small amount of iodophor solution into the gingival pocket 1~3 times a day and rinse the mouth with warm water. 2. Medication: Oral antibacterial drugs, such as metronidazole, to help relieve the symptoms of inflammation. 3. Incision and drainage: When pus is formed, incision and drainage should be made in time. 4. Excision of gingival flap or removal of wisdom teeth after inflammation subsides: after inflammation subsides, if the position of wisdom teeth is normal and can be retained, the gingival flap will be excised to eliminate the blind pocket; if the wisdom teeth are blocked or malpositioned, the wisdom teeth can be removed. Medications should be used under the guidance of a doctor, and it is recommended to visit a hospital to receive professional treatment.