Persistent or frequent mouth ulcers: when should they be examined?

A typical aphthous ulcer is a small, painful mouth ulcer without bleeding and is not contagious. Other diseases can cause different mouth lesions: do not assume every sore is an aphthous ulcer, especially when its appearance or context is unusual.

Seek assessment if a lesion does not heal or lasts more than two weeks, is larger than one centimetre, or there are very many lesions, particularly more than ten. Also report episodes recurring several times a year; these reference points do not mean waiting if you feel unwell.

Medical advice is also needed for fever, marked tiredness, difficulty eating with weight loss, joint pain, diarrhoea or recent lesions elsewhere, particularly on the genitals. Describing these signs helps the doctor investigate a cause without self-diagnosis.

A tooth, denture or appliance can injure the lining of the mouth. Have friction checked by a dentist rather than adjusting an appliance yourself. While awaiting advice, soft, cool foods can reduce discomfort.

If lesions appear during treatment, tell the doctor and provide your medicine list. Do not choose systemic treatment on your own. Ameli states that local mouth anaesthetics must never be used in children or older people because of the risk of aspiration.

The doctor examines the lesions and their course. For severe, recurrent or persistent ulcers, they may suggest suitable investigations, sometimes blood tests or a biopsy. These tests and treatments are not automatic: they depend on what the assessment finds.