Does mouth cancer cause a mouth sore that does not heal?

A mouth cancer sore may appear on the tongue, gums, inner cheek, roof of the mouth, or other oral tissues. It may look like an ulcer, a red or white patch, or an area that bleeds, thickens, or becomes painful. Changes in nearby tissues can also cause numbness, a lump, loose teeth, or difficulty moving the tongue or jaw.

Most mouth sores are caused by irritation, infection, injury, or another non-cancer condition. Appearance alone cannot settle the cause, so a sore that persists or changes needs an examination by a dentist or doctor.

Arrange an oral examination for a sore that does not heal, returns, enlarges, or becomes harder to tolerate. Tell the clinician about tobacco or alcohol exposure, sharp teeth, dentures, recent dental work, medicines, and any difficulty eating or speaking.

The clinician may inspect the whole mouth and neck and may arrange further tests, including a biopsy, if an area looks concerning. Keep the area clean, avoid picking it, and avoid foods or products that clearly irritate it while waiting for advice.

Seek urgent help for heavy bleeding, rapidly increasing swelling, inability to swallow fluids, breathing difficulty, or sudden severe weakness. These problems can require immediate treatment, regardless of the sore's cause.

What might be causing this sore, and does it need a biopsy? Could a tooth, denture, or medicine be irritating it? How should I manage pain and eating while it is being assessed? When should I return if it does not improve?