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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.


Seek care immediately if:

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

Contact your healthcare provider if:

  • 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.


You may need any of the following:

  • Pain medicine may be given as a cream, gel, or mouthwash.
  • Steroid medicine may be given to decrease redness, swelling, and pain.
  • Take your medicine as directed. Contact your healthcare provider if you think your medicine is not helping or if you have side effects. Tell him or her 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 doctor as directed:

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

Eat soft, plain foods until your canker sores heal:

Examples include yogurt, eggs, and creamy soups. You may need to change some foods you usually eat. Do not have crunchy, dry, or salty foods, such as dry toast, popcorn, or chips. These can cause pain. Do not have foods or drinks that contain citric acid, such as grapefruit, orange juice, lemons, and limes. These may make your pain worse or cause more sores to form.

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.

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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.

Learn more about Canker Sores (Discharge Care)

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.