The appearance of pus at the gums may be periodontal abscess, periapical abscess, etc. The surrounding tissues within the abscess are the result of the reaction to inflammation, and it can not be simply said that there is no poison, as follows. The pus inside the abscess, its main components include bacteria and their products, neutrophils, lymphocytes, plasma cells, macrophages and so on. Among them, bacteria and their products can damage the periodontal membrane, neutrophils will release lysosomes when phagocytosis of bacteria and their products, which can lead to periapical periodontal necrosis and the formation of a larger abscess. The bone marrow cavity of the alveolar bone around the abscess can also be infiltrated with neutrophils, and if the inflammation is not controlled, it can develop into alveolar osteomyelitis, i.e. acute alveolar abscess. If the above symptoms occur, it is recommended to go to the hospital in time to receive professional treatment as soon as possible.