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Letter M

Mouth ulcers

Also known as: Canker sores, Aphthous ulcers

Mouth ulcers symptom guide: what it can mean, possible causes, and when to seek care. Educational only.

Overview

Mouth ulcers (aphthous) often heal within a week. Stress, minor trauma, or nutrient gaps can contribute. Large, lasting, or very frequent ulcers deserve evaluation.

Possible causes

  • Aphthous ulcers
  • Minor trauma (cheek bite)
  • Stress
  • Iron/B12 deficiency
  • Food allergy (less often)

When to see a doctor

Visit a clinic if ulcers last more than 2 weeks, are large, or come with fever.

Related conditions