Back gum swollen and hurts
Painful swelling behind a back tooth may come from gum inflammation, trapped food, eruption, decay, or an abscess.
The short answer
Painful swelling behind a back tooth can result from trapped food, gum inflammation, a partially erupted wisdom tooth, decay, or an infection around the tooth. The location and cause cannot be confirmed from symptoms alone because gum and tooth pain can overlap.
Which tissues may swell behind a back molar?
The area behind a molar may contain the gum flap over an erupting third molar, the distal gum pocket of the second molar, or the lining of the cheek. Swelling there can trap plaque and bacteria or reflect inflammation inside the tooth.
What can you do for a painful swollen back gum?
Rinse gently with warm water, brush the accessible surfaces, and clean between the back teeth without forcing an object into the swollen area. Use an over-the-counter pain medicine only if it is suitable for you and follow its label; do not place aspirin on the gum.
When should painful back gum swelling be examined?
Arrange a dental examination promptly when swelling or pain persists, returns, or affects chewing. Seek emergency help for facial or neck swelling, fever with worsening dental pain, difficulty swallowing, difficulty breathing, or inability to open the mouth normally.
What should you ask about a swollen back gum?
Ask whether the swelling is around an erupting wisdom tooth, a gum pocket, or a decayed tooth, and whether an X-ray is needed. Ask which treatment removes the cause, such as cleaning, a filling, root-canal treatment, extraction, or gum care.
Frequently asked questions
Could a wisdom tooth cause swelling behind the molar?
Yes. A partially erupted wisdom tooth can leave a gum flap where plaque and food collect, causing localized inflammation and pain.
Will salt water cure the swelling?
A gentle rinse may soothe irritated tissue and remove debris, but it does not treat decay, an abscess, or a persistent gum pocket.
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.