Canker Sores
Medically reviewed by Drugs.com. Last updated on Apr 6, 2025.
What are 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 1 or more sores at a time, and they may grow in clusters.
What increases my risk for canker sores?
The cause of canker sores is not known. Your risk is increased if anyone in your family gets canker sores. Any of the following may also increase your risk:
- Conditions such as celiac disease, HIV, lupus, or Crohn disease
- Hormone changes during a woman's monthly period
- Allergies or sensitivities to foods
- Mouth injuries caused by biting, dentures, braces, or brushing your teeth too hard
- Medicines such as NSAIDs, chemotherapy, and some blood pressure medicines
- Low levels of iron, zinc, vitamin B, vitamin D or folic acid
- Stress, depression, or anxiety
What are the signs and symptoms of canker sores?
- One or more sores on the back or floor of your mouth, the inner side of your cheeks and lips, or under your tongue
- Round or oval-shaped red sores that may have a gray or yellow center
- Pain or burning in your mouth
- Difficulty chewing and swallowing
How are canker sores diagnosed?
Your healthcare provider will ask about your symptoms and examine your mouth. Your provider will ask about your medical history and if you take any medicines. Tell your provider if you or anyone in your family gets canker sores.
How are canker sores treated?
Canker sores cannot be cured. The sores may go away for a time, and then come back again. Medicines to decrease pain and inflammation may be given.
Treatment options
The following list of medications are related to or used in the treatment of this condition.
How can I manage my symptoms and prevent canker sores?
- Eat soft, plain foods until your canker sores heal. Foods such as eggs, yogurt, soups, rice, and pasta may be easier for you to eat. Do not eat crunchy, dry, salty, or spicy foods. Examples include dry toast, popcorn, or chips. These can cause pain. Do not have foods or drinks that contain citric acid, such as grapefruit or orange juice. These may make your pain worse or cause more sores to form.
- Gently brush your teeth and tongue. Use a soft toothbrush. Avoid using toothpaste that contains sodium lauryl sulfate (SLS). Toothpaste with SLS can increase your pain, make your sores heal slower, and cause more sores to form.
- Care for your mouth. Clean dentures, mouth guards, and devices to straighten or whiten teeth often. Tell your dentist if your braces or dentures do not feel comfortable. Your dentist can help these devices fit better. Regular mouth care can help prevent sores.
- Manage other health conditions. Follow your healthcare provider's advice on how to manage conditions that increase your risk of canker sores. Ask your provider about medicines you are taking and if they cause canker sores.
When should I call my doctor?
- You cannot eat or drink because of your mouth pain.
- 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.
Care Agreement
You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. 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.© Copyright Merative 2025 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.
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