Swollen under lip: causes and next steps

“Under the lip” may mean the skin below it, the inner lining, or the gum area, and each location offers different clues. Skin swelling may follow contact with cosmetics, shaving, friction, or a bite. Inner-lip swelling can follow accidental biting or a blocked minor salivary gland. Gum tenderness, a bad taste, fever, or tooth pain points toward a dental source. Angioedema can cause deeper swelling of the lips and face and may develop quickly; learn more about [Angioedema](/conditions/angioedema/). A clinician may need to examine the mouth directly.

Look gently for a visible cut, blister, ulcer, redness, or dental swelling without poking the tissue. Stop any newly introduced balm, toothpaste, cosmetic, or food that causes burning. A cool compress on the outside may reduce discomfort. Choose soft, non-spicy foods if chewing hurts, keep drinking fluids, and maintain gentle oral hygiene. Do not pop a blister or drain a lump. If you suspect a medicine or food reaction, note the exposure and contact a healthcare professional for individualized advice rather than taking a borrowed treatment.

Emergency care is needed for swelling of the tongue or throat, breathing difficulty, inability to swallow, drooling, a muffled voice, faintness, or rapidly worsening facial swelling. Obtain prompt care for fever with dental pain, spreading redness, pus, severe tenderness, or trouble opening the mouth. Book an appointment when swelling lasts beyond a short period, repeatedly returns, or leaves a firm area or ulcer that does not heal.

Ask which exact tissue is swollen, whether your teeth or gums need checking, whether a recent product or medicine could be involved, and what personal action plan to follow if swelling recurs.