Most ulcers are not cancer, but persistence matters
A mouth ulcer may follow accidental biting, rubbing from a sharp tooth or denture, or recurrent aphthous ulceration. Many settle within one or two weeks. An ulcer lasting longer than three weeks should be assessed by a dentist or doctor. Arrange an earlier assessment if it looks unusual, is worsening or is accompanied by other concerning changes.
A persistent red or white patch, unexplained lump, altered sensation, difficulty swallowing or a neck lump also deserves examination. These findings have several possible causes; a photograph or online description cannot establish the diagnosis.
What the clinician will ask
The history includes when the lesion appeared, whether it has changed, local trauma, medicines, tobacco and alcohol use, and other symptoms. The examination may identify a mechanical cause, but a lesion should not be indefinitely attributed to a sharp edge without checking that it heals after the cause is addressed.
Why a biopsy may be recommended
A biopsy removes a small tissue sample, or sometimes the whole small lesion, for examination by a pathology laboratory. It may be needed to distinguish conditions that look similar. A biopsy recommendation does not itself mean that cancer has been diagnosed.
The clinician explains the site, anaesthesia, possible bleeding or discomfort, and how results will be communicated. Specialist referral may be appropriate depending on the findings.
Do not delay a review by repeatedly treating symptoms
Avoid applying caustic home remedies or using leftover medication. If an appointment or biopsy has been advised, symptom relief is not a reason to cancel it. Ask who will contact you with results and when to follow up if you have not heard back.
Seek emergency care for difficulty breathing, rapidly increasing swelling or significant uncontrolled bleeding.
