Swollen back gum one side
One-sided swelling behind a molar can come from trapped food, gum inflammation, a partially erupted wisdom tooth, decay, or an abscess.
The short answer
Pericoronitis affects gum around a partly erupted tooth, while decay or root infection can swell tissue near a molar. Examination, tooth testing, and sometimes an X-ray identify the source.
How can you care for swelling behind a back tooth?
Rinse gently, clean without digging into the swelling, and avoid hard foods on that side. Do not pop the swelling or apply aspirin or caustic chemicals.
When should persistent one-sided gum swelling be checked?
Seek prompt care for persistent swelling, pain, bad taste, pus, fever, or limited mouth opening. Facial swelling or trouble swallowing or breathing is urgent.
Which tooth tests or treatments might be needed?
Ask which tooth or tissue is involved, whether imaging is needed, and whether cleaning, drainage, restoration, or extraction is appropriate.
Frequently asked questions
What is the key point?
Pericoronitis affects gum around a partly erupted tooth, while decay or root infection can swell tissue near a molar. Examination, tooth testing, and sometimes an X-ray identify the source.
What should I avoid?
Seek prompt care for persistent swelling, pain, bad taste, pus, fever, or limited mouth opening. Facial swelling or trouble swallowing or breathing is urgent.
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Who wrote this page
This library is published by Dental Nation, a licensed dental group practising in the United Arab Emirates. Pages are written and overseen by the same clinical team that treats patients in our clinics, and are held to a fixed editorial standard for safety and accuracy.
This page is patient education, not medical advice, and cannot replace an examination. Anything urgent — facial swelling, trauma, uncontrolled bleeding or severe pain — needs a dentist or emergency care now.