Swollen lip after biting it: what to know

A bite can bruise the lip, create a small cut, or leave a deeper wound inside the mouth. Swelling may build soon after the injury, while a bruise can change colour as it settles. A sharp tooth, dental appliance, or repeated biting can keep reopening the area. Pain should gradually ease; increasing warmth, redness, pus, fever, or a bad taste may suggest infection rather than routine healing.

Wash your hands, then apply gentle pressure with clean gauze or cloth if the lip is bleeding. Use a wrapped cold pack for short periods, taking breaks so the skin does not become numb. Rinse the mouth with clean water after eating and choose soft, cool foods while chewing carefully. Avoid alcohol-based mouthwash, smoking, and picking at a scab. Do not place aspirin directly on the wound. A dentist can check a sharp tooth or damaged dental work.

Get urgent help if bleeding does not stop with firm pressure, the cut crosses the lip edge, the wound is deep or gaping, a tooth is loose, or breathing and swallowing become difficult. Seek medical or dental assessment for worsening pain, spreading redness, pus, fever, or swelling that is not settling. Sudden swelling away from the injured area, or swelling of the tongue or throat, can signal a separate reaction; learn about [Angioedema](/conditions/angioedema/).

Does the cut need closure or a dental repair? Is there a tooth edge causing repeated trauma? What pain relief and mouth care are appropriate for me? What changes would mean the wound is infected?