Munson Health
Aphthous Ulcers

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by Norwood D

(Canker Sores; Aphthous Stomatitis)



Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor will most likely be able to tell the difference between a canker sore or more serious mouth sore by looking at it. To rule out other problems your doctor may do the following:
  • Biopsy—a small sample of the sore will be sent to a lab for closer examination
  • Blood culture or tests—to look for signs of an infection or other systemic health conditions
It is especially important to examine mouth sores that do not heal within two weeks. They may be a sign of cancer.


American Academy of Family Physicians

American Dental Association



Canadian Family Physician

Health Canada



Aphthous stomatitis. EBSCO DynaMed website. Available at: Updated August 31, 2012. Accessed December 7, 2012.

Beers MH, Berkow R. The Merck Manual. 17th ed. West Point, PA: Merck and Co; 1999.

Canker sores. American Family Physicians Family Doctor website. Available at: Accessed December 7, 2012.


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