Canker sores

Canker sores

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Canker sores are small-sized, shallow ulcers that appear in your mouth. Most cases of canker sores are harmless and heal within a few days but they can cause discomfort when you’re eating or trying to talk as they can be painful. While the precise cause of canker sores is unknown, it is thought to be stress and tissue injury.

Certain foods such as citrus fruits or vegetables can trigger canker sores or worsen the problem.

Other causes of canker sores also include a sharp tooth surface and dental appliances, such as braces and improperly placed dentures.

Some of the complex canker sores cases are caused by an underlying medical condition. Examples of these are an impaired immune system, nutritional problems, folic acid, an iron deficiency, or a gastrointestinal tract disease.

Signs and symptoms of canker sores

Canker sores
Certain foods such as citrus fruits or vegetables can trigger canker sores or worsen the problem.
  • Aching sore within the mouth.
  • A burning or tingling sensation before a sore appears.
  • The presence of sores in your mouth that are rounded and have a whitish or grayish color with a red edge or border.

If you have severe canker sores, these additional symptoms may appear:

  • Sluggishness
  • Enlarged lymph nodes.


The pain that you feel from the sores generally lessens as days pass, and the sores will heal by themselves without any kind of treatment. Cases of canker sores that undergo treatment with dental lasers will almost completely relieve all of the symptoms immediately. You should talk to your dentist first about the procedure.


There is no available cure and they often persist, but you can help reduce the frequency of canker sores by:

  • Avoid foods that can irritate the mouth such as citrus fruits, acidic vegetables, and spicy foods.
  • Brush your teeth using a soft-bristled toothbrush after every meal and flossing daily.


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