Gums hurting in back of mouth
Pain at the back of the mouth can come from gum inflammation, a wisdom tooth, food trapping, trauma, or an infection around a molar.
The short answer
Pain in the back gums commonly comes from trapped food, gum inflammation, a wisdom tooth, a cheek injury, or infection around a molar, and the cause is found by examining the area. The dentist may inspect the gum pocket and take an X-ray if a tooth is partly erupted or difficult to see.

What is the direct answer?
What does this question mean?
The gum behind a last molar can become inflamed when a wisdom tooth is partly covered by a gum flap called an operculum. Plaque and food can collect there, while a cavity, cracked tooth, periodontal pocket, or ulcer can create similar soreness farther forward.
What can you do next?
Gently clean the back teeth with a small-headed brush and rinse with warm salt water if it does not increase pain. Avoid picking under the gum flap or applying caustic substances, and choose soft foods until the area can be examined.
When should you seek dental care?
Book an examination when pain lasts more than a short episode, keeps returning, or comes with bleeding, bad taste, swelling, or trouble chewing. Fever, facial swelling, limited mouth opening, or difficulty swallowing needs urgent assessment.
What should you ask the dentist?
Ask whether the pain is from a wisdom tooth, a molar, the gum pocket, or an ulcer, and whether an X-ray shows the tooth position. Ask whether cleaning, a filling, gum treatment, removal of a wisdom tooth, or another option addresses the cause.
Frequently asked questions
Can food stuck behind a tooth cause gum pain?
Yes. Trapped food can press on tissue and feed local inflammation, although persistent pain should be checked for decay or infection.
Does back gum pain always mean a wisdom tooth must come out?
No. The cause may be cleaning difficulty, decay, gum disease, or trauma, and removal is only one possible treatment.
