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Canker Sores


Canker sores are small ulcers that develop inside your mouth. Ulcers are open sores that may be shallow or deep. You may have one or more sores at a time, and they may grow in clusters.



  • Pain medicine: This may be given to decrease pain in your mouth. This medicine may be given as a cream, gel, or mouthwash.

  • Steroid medicine: This may be given to decrease redness, swelling, and pain.

  • Supplements: Ask your primary healthcare provider if you should have more of certain vitamins and minerals to help prevent canker sores.

  • Take your medicine as directed. Call your healthcare provider if you think your medicine is not helping or if you have side effects. Tell him if you are allergic to any medicine. Keep a list of the medicines, vitamins, and herbs you take. Include the amounts, and when and why you take them. Bring the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency.

Follow up with your healthcare provider as directed:

Write down your questions so you remember to ask them during your visits.

Change the foods you eat:

Avoid crunchy, dry, and salty foods such as dry toast, popcorn, and chips because they can cause pain. Avoid foods and drinks that contain citric acid such as grapefruit, orange juice, lemons, and limes. These foods may make your pain worse or cause more sores to form. Eat soft, plain foods until your canker sores heal.

Mouth care:

Gently brush your teeth and tongue every day. Use a soft toothbrush. If you have dentures, clean them every day. If your braces or dentures do not feel comfortable, have a dentist check them to see that they fit well.

Contact your primary healthcare provider if:

  • You have chills or a fever.

  • Your canker sores are not gone after 3 to 4 weeks.

  • Your pain does not go away after you take medicines.

  • Your sores are getting worse or you are getting more sores, even after treatment.

  • You have questions or concerns about your condition or care.

Return to the emergency department if:

  • You cannot eat or drink because of your mouth pain.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.