Site Map

Canker sore

Aphthous ulcer; Ulcer - aphthous

A canker sore is a painful, open sore in the mouth. Canker sores are white or yellow and surrounded by a bright red area. They are not cancerous.

A canker sore is not the same as a fever blister (cold sore).

Images

Canker sore
Mouth anatomy
Canker sore (aphthous ulcer)
Fever blister

I Would Like to Learn About:

Causes

Canker sores are a common form of mouth ulcer. They may occur with viral infections. In some cases, the cause is unknown.

Canker sores may also be linked to problems with the body's immune system. The sores may also be brought on by:

Other things that can trigger canker sores include:

Anyone can develop a canker sore. Women are more likely to get them than men. Canker sores may run in families.

Symptoms

Canker sores most often appear on the inner surface of the cheeks and lips, tongue, upper surface of the mouth, and the base of the gums.

Symptoms include:

Less common symptoms include:

Pain often goes away in 7 to 10 days. It can take 1 to 3 weeks for a canker sore to completely heal. Large ulcers can take longer to heal.

Exams and Tests

Your health care provider can often make the diagnosis by looking at the sore.

If canker sores persist or continue to return, tests should be done to look for other causes, such as erythema multiforme, drug allergies, herpes infection, and bullous lichen planus.

You may need further testing or a biopsy to look for other causes of mouth ulcers. Canker sores are not cancer and do not cause cancer. There are types of cancer, however, that may first appear as a mouth ulcer that does not heal.

Treatment

In most cases, the canker sores go away without treatment.

Try not to eat hot or spicy foods, which can cause pain.

Use over-the-counter medicines that ease pain in the area.

Medicines prescribed by your provider may be needed for severe cases. These may include:

Brush your teeth twice a day and floss your teeth every day. Also, get routine dental check-ups.

In some cases, gastric acid-reducing medicines can decrease the discomfort. 

Outlook (Prognosis)

Canker sores almost always heal on their own. The pain should decrease in a few days. Other symptoms disappear in 10 to 14 days.

When to Contact a Medical Professional

Call your provider if:

Related Information

Erosion
Benign
Herpetic stomatitis
Mouth ulcers
Numbness and tingling
Malaise
Folic acid in diet
Vitamin B12
Food allergy
Cellulitis
Ludwig angina

References

Daniels TE, Jordan RC. Diseases of the mouth and salivary glands. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 425.

Dhar V. Common lesions of the oral soft tissues. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 341. 

Lingen MW. Head and neck. In: Kumar V, Abbas AK, Aster JC, eds. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 16.

BACK TO TOP

Review Date: 5/22/2019  

Reviewed By: Josef Shargorodsky, MD, MPH, Johns Hopkins University School of Medicine, Baltimore, MD. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

ADAM Quality Logo

A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics. This site complies with the HONcode standard for trustworthy health information: verify here.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2021 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.