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Mouth Sores

Harvard Health Publications
2007 Copyright Harvard Health Publications


I have recurring sores in my mouth, most generally on the sides of my tongue, and the tip of my tongue gets very tender and sore. Do I have a vitamin deficiency? What else could be the cause of this?


The most common cause of recurrent sores on the tongue is aphthous stomatitis, or canker sores. These sores usually occur one or two at a time, last seven to 10 days, and are quite painful, especially when eating acidic foods. They may recur several times a year or even every month or two. The cause is unknown but they are otherwise harmless and are not clearly associated with any single nutritional deficiency or illness. There are some research studies suggesting that up to 20 percent of canker sores are due to lack of folic acid, iron or vitamin B12, but other researchers have been unable to confirm this. A general medical evaluation to identify one of these problems should be able to determine whether your tongue sores are related to a nutritional deficiency. In addition, it might be wise to take a multivitamin (as is often recommended routinely, even for people without canker sores).

Otherwise, treatment of canker sores includes topical pain relievers (such as benzocaine found in many over-the-counter preparations), warm water rinses and avoiding foods that aggravate the pain. For severe cases, prescription medications, including rinses with corticosteroids, can provide relief.

A number of other conditions can cause oral ulcers:

  • Viral infection - Herpes infection can cause clusters of small blisters (often called fever blisters or cold sores), usually on outside of the lip rather than the tongue; other viral infections can cause tongue sores, but they do not usually recur.

  • Intestinal diseases, including Crohn's disease or Celiac Sprue - These are conditions marked by intestinal inflammation or colitis; they are usually associated with abdominal pain, cramps and chronic diarrhea.

  • Autoimmune disease – These are relatively rare diseases in which the body's immune system mistakenly attacks tissues in the body; examples include:

    • Behcet's disease – Characterized by multiple oral and genital ulcers lasting weeks or even longer; in addition, inflammation in the eye (with eye pain and reduced vision), joints and other organs may develop

    • Systemic lupus erythematosus (SLE, or lupus) – Most commonly marked by skin rash and joint pain; there may be inflammation in other parts of the body, including the lungs, heart, and kidneys

    • Reiter's disease - An infection (usually a sexually transmitted disease or a diarrheal illness) triggers the body's immune system to attack other parts of the body; arthritis, painful urination and eye inflammation are typical features.

  • Food reaction – Allergic or chemical reactions may cause sores in the mouth soon after contact, just as a skin rash can follow contact with poison ivy.

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Harvard Health Publications Source: from the Harvard Health Publications Family Health Guide, Copyright © 2007 by President and Fellows of Harvard College. All rights reserved.

Used with permission of StayWell.

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