Swelling in the middle part of the mouth can be caused by allergies, folliculitis, sebaceous cysts and so on. 1. Allergy: generally caused by pollen, dust, food and other allergens, manifested as itching, redness, swelling and other symptoms, which will appear in the oral cavity of the phenomenon of swelling, you can use loratadine, levocetirizine and other drugs under the advice of the doctor for treatment. 2. Folliculitis: generally caused by bacterial infection, manifested as redness, pain, swelling and other symptoms, which will appear in the oral human center part of the swelling phenomenon, you can use cefdinir, azithromycin and other drugs under the guidance of the doctor for treatment. 3. Sebaceous cysts: generally due to the sebaceous gland duct blockage, which will appear in the oral human center part of the swelling phenomenon, can be removed under the operation of the doctor. Swelling in the middle of the mouth need to go to the hospital in time to confirm the diagnosis, follow the doctor’s instructions for standardized treatment.