Patient Education

Mouth Sores (Oral Ulcers)

Mouth sores are common and often painful. Most heal on their own, but identifying the cause is important for correct treatment.

Mouth sores (oral ulcers) can affect people of all ages. While many ulcers are harmless and self-limiting, some may indicate infection, nutritional deficiency, systemic disease, or even early cancer.

Common Types & How to Differentiate

1. Recurrent Aphthous Ulcers (Most Common)

  • Round/oval ulcers with yellow-white base and red halo
  • Occurs on inner cheeks, lips, floor of mouth, underside of tongue
  • Very painful
  • Minor: heals in 7–10 days
  • Major: larger, may take weeks and scar
  • Herpetiform: multiple tiny clustered ulcers

Triggers: Stress, trauma, vitamin B12/iron/folate deficiency, spicy food, hormonal changes

2. Traumatic Ulcers

  • Caused by sharp tooth, braces, denture, cheek bite
  • Irregular margins
  • Heals after removing cause

3. Herpetic Ulcers (HSV)

  • Primary infection: fever + many painful ulcers (children)
  • Recurrent herpes on gums or hard palate
  • Often preceded by tingling/burning

4. Systemic Disease–Associated Ulcers

  • Behçet’s disease
  • Iron/B12 deficiency
  • Celiac disease
  • Inflammatory bowel disease
  • HIV

5. Drug / Chemical Ulcers

  • NSAIDs, methotrexate, nicorandil
  • Chemical burns from aspirin or clove oil misuse

6. Premalignant / Malignant Ulcers

  • Does not heal after 2 weeks
  • Hard or rolled borders
  • Painless initially
  • May have neck lymph node swelling

Patient Care Advice

  • Use soft toothbrush
  • SLS-free toothpaste
  • Avoid spicy and acidic food
  • Good sleep and hydration
  • Do NOT place clove oil or aspirin on ulcers

Related Articles

Ulcer Not Healing?

Any mouth ulcer lasting more than 2 weeks should be evaluated by a dentist.

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