Why Do Mouth Sores Keep Returning?
Frequent mouth sores are often canker sores, but repeated or persistent ulcers need an examination. Learn what may be behind constant mouth ulcers.
The short answer
Frequent mouth sores are usually recurrent canker sores, but ulcers that keep returning, last longer than expected, or come with other symptoms need a dental or medical assessment. A dentist checks the ulcer, nearby teeth and gums, and your medical history rather than diagnosing from frequency alone.
What does a recurring sore in the mouth usually describe?
A mouth sore is a break in the lining of the mouth, often on the inner lip, cheek, tongue edge, or soft palate. Common triggers include local trauma, sharp teeth, irritating foods, stress, and some medicines; repeated ulcers can also occur with nutritional deficiency, immune conditions, or gastrointestinal disease.
How can you reduce irritation while a mouth sore heals?
Avoid picking the sore and choose soft, mild foods while it heals; a soft toothbrush and gentle rinsing can reduce irritation. Note its location, duration, possible triggers, medicines, and associated symptoms so the clinician can decide whether an oral examination or medical tests are appropriate.
When should recurring or slow-healing mouth sores be examined?
Arrange an examination when sores recur often, do not heal, are unusually large or painful, or make eating and drinking difficult. Seek urgent care for facial swelling, trouble breathing or swallowing, dehydration, high fever, or rapidly spreading infection signs.
What might be causing the sore and what should you ask?
Ask whether the appearance fits a canker sore, trauma, fungal infection, or another lesion, and whether a sharp tooth or dental appliance is contributing. Also ask what examination or blood tests may be needed and which treatment is appropriate for the suspected cause.
Frequently asked questions
Can stress cause mouth sores?
Stress can coincide with recurrent canker sores, although the clinician should consider other triggers when sores keep returning.
Should I put aspirin on an ulcer?
Do not place aspirin directly on the sore because it can chemically irritate the mouth lining.
Who wrote this page
This library is published by Dental Nation, a licensed dental group practising in the United Arab Emirates. Pages are written and overseen by the same clinical team that treats patients in our clinics, and are held to a fixed editorial standard for safety and accuracy.
This page is patient education, not medical advice, and cannot replace an examination. Anything urgent — facial swelling, trauma, uncontrolled bleeding or severe pain — needs a dentist or emergency care now.