A swollen gum pouch may be a result of apical infection or periodontitis. A swollen gum is also a clinically common gum abscess, which is an inflammatory reaction of soft tissue. The gum abscess may be caused by tooth decay, bacterial infection of the pulp tissue, causing pus necrosis of the pulp tissue, and if timely and effective root canal treatment is not performed, the inflammation will break through the gums to form a gum abscess. A swollen gum may also be caused by periodontitis. If you do not brush your teeth in time after eating, food debris will accumulate around your teeth and form periodontitis, resulting in bleeding gums, redness and pus, formation of periodontal pockets, and sometimes gum abscesses. A swollen gum pouch may also be a benign tumor of the gums, such as a gingival tumor. Sometimes gum tumors can also occur during pregnancy, which may be related to changes in hormone levels in the body during pregnancy. It can be caused by a proliferation of certain medications, such as phenytoin sodium. Or it may be a malignant tumor of the gums, such as gum cancer, which requires appropriate soft tissue pathology to confirm the diagnosis. So a swollen gum may be an abscess caused by necrosis of the dental nerve, or it may be periodontitis or a gum tumor.