Understanding the difference between a canker sore and other mouth sores is important for proper treatment and relief. While they may look similar, there are key signs that can help you identify a canker sore.

What Is a Canker Sore?

A canker sore, also known as an aphthous ulcer, is a small, shallow lesion that develops on the soft tissues inside your mouth. They are not contagious and usually heal on their own within one to two weeks.

Signs and Symptoms of a Canker Sore

  • Location: Inside the mouth, often on the tongue, soft palate, or inside of the cheeks.
  • Appearance: Round or oval with a white or yellow center and a red border.
  • Pain: Often painful, especially when eating or drinking.
  • Size: Usually small, less than 1 centimeter in diameter.
  • Number: Can appear as a single sore or multiple sores at once.

How to Differentiate from Other Mouth Sores

Other mouth sores, such as cold sores or canker sores caused by infections, have different characteristics. Recognizing these differences can help you determine the cause.

Cold Sores

Cold sores, caused by the herpes simplex virus, typically appear on the outside of the mouth, around the lips. They are contagious and often start as blisters before crusting over.

Trauma or Injury

Injuries from biting, dental work, or sharp foods can cause sores that may look similar but usually heal quickly once the injury heals.

When to See a Healthcare Professional

If a sore persists longer than two weeks, worsens, or is accompanied by other symptoms like fever or difficulty swallowing, consult a healthcare provider. They can diagnose the cause and recommend appropriate treatment.