Gums swollen at back of mouth

Swelling behind a back tooth can reflect an erupting wisdom tooth, trapped food, gum inflammation, decay, or infection.

The area contains gum over or beside a wisdom tooth; a partly erupted tooth can leave a flap where plaque and food collect, causing pericoronitis.

Rinse gently with lukewarm water, brush reachable surfaces, and avoid packing food into the area; a dentist may irrigate, image, restore, treat, or remove the tooth.

Arrange prompt care for worsening pain, pus, fever, facial swelling, or limited mouth opening; swallowing or breathing difficulty is urgent.

Ask whether the wisdom tooth position, neighboring molar, gum flap, decay, or bone changes explain the swelling and how to clean it.