Tests aren't needed to diagnose canker sores. Your doctor or dentist can identify them with a visual exam. In some cases, you may have tests to check for other health problems, especially if your canker sores are severe and ongoing.
Treatment usually isn't necessary for minor canker sores, which tend to clear on their own in a week or two. But large, persistent or unusually painful sores often need medical care. A number of treatment options exist.
If you have several canker sores, your doctor may prescribe a mouth rinse containing the steroid dexamethasone (dek-suh-METH-uh-sown) to reduce pain and inflammation or lidocaine to reduce pain.
Over-the-counter and prescription products (pastes, creams, gels or liquids) may help relieve pain and speed healing if applied to individual sores as soon as they appear. Some products have active ingredients, such as:
- Benzocaine (Anbesol, Kank-A, Orabase, Zilactin-B)
- Fluocinonide (Lidex, Vanos)
- Hydrogen peroxide (Orajel Antiseptic Mouth Sore Rinse, Peroxyl)
There are many other topical products for canker sores, including those without active ingredients. Ask your doctor or dentist for advice on which may work best for you.
Oral medications may be used when canker sores are severe or do not respond to topical treatments. These may include:
- Medications not intended specifically for canker sore treatment, such as the intestinal ulcer treatment sucralfate (Carafate) used as a coating agent and colchicine, which is normally used to treat gout.
- Oral steroid medications when severe canker sores don't respond to other treatments. But because of serious side effects, they're usually a last resort.
Cautery of sores
During cautery, an instrument or chemical substance is used to burn, sear or destroy tissue.
- Debacterol is a topical solution designed to treat canker sores and gum problems. By chemically cauterizing canker sores, this medication may reduce healing time to about a week.
- Silver nitrate — another option for chemical cautery of canker sores — hasn't been shown to speed healing, but it may help relieve canker sore pain.
Your doctor may prescribe a nutritional supplement if you consume low amounts of important nutrients, such as folate (folic acid), vitamin B-6, vitamin B-12 or zinc.
Related health problems
If your canker sores relate to a more serious health problem, your doctor will treat the underlying condition.
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
Lifestyle and home remedies
To help relieve pain and speed healing, consider these tips:
- Rinse your mouth. Use salt water or baking soda rinse (dissolve 1 teaspoon of baking soda in 1/2 cup warm water).
- Dab a small amount of milk of magnesia on your canker sore a few times a day.
- Avoid abrasive, acidic or spicy foods that can cause further irritation and pain.
- Apply ice to your canker sores by allowing ice chips to slowly dissolve over the sores.
- Brush your teeth gently, using a soft brush and foaming-agent-free toothpaste such as Biotene or Sensodyne ProNamel.
Preparing for your appointment
Your doctor or dentist can diagnose a canker sore based on its appearance. Here's some information to help you get ready for your appointment.
Information to gather
Before your appointment make a list of:
- Your symptoms, including when they first started and how they may have changed or worsened over time
- All your medications, including over-the-counter medications, vitamins or other supplements, and their doses
- Any other medical conditions, to see if any relate to your symptoms
- Key personal information, including any recent changes or emotional stressors in your life
- Questions to ask your doctor or dentist to make your visit more efficient
Here are some basic questions to ask:
- Do I have a canker sore?
- If so, what factors may have contributed to its development? If not, what else could it be?
- Do I need any tests?
- What treatment approach do you recommend, if any?
- What self-care steps can I take to ease my symptoms?
- Is there anything I can do to speed up healing?
- How soon do you expect my symptoms will improve?
- Is there anything I can do to help prevent a recurrence?
Don't hesitate to ask any other questions during your appointment.
What to expect from your doctor or dentist
Be ready to answer questions from your doctor or dentist, such as:
- What are your symptoms?
- When did you first notice these symptoms?
- How severe is your pain?
- Have you had similar sores in the past? If so, have you noticed if anything in particular seemed to trigger them?
- Have you been treated for similar sores in the past? If so, what treatment was most effective?
- Have you had any recent dental work?
- Have you recently experienced significant stress or major life changes?
- What is your typical daily diet?
- Have you been diagnosed with any other medical conditions?
- What medications are you taking, including prescription and over-the-counter medications, vitamins, herbs and other supplements?
- Do you have a family history of canker sores?