If you’ve ever had a canker sore, you know it’s unpleasant – it hurts! You might wonder what canker sores are, if they are dangerous, and what, if anything, you can do to make them go away. We’ll give you the answers to those questions in this blog. 

What Is a Canker Sore?

canker soreA canker sore, more formally known as an aphthous ulcer, is a small, painful but shallow lesion that develops in your mouth, either on your gums or your soft tissues. If you have a sore on your lips or face, it’s not a canker sore, it’s a cold sore. A canker sore is painful and can make eating or drinking more difficult. Unlike a cold sore, however, it’s not contagious. 

Women experience canker sores twice as often than men, usually developing them first during either childhood or adolescence. It’s not known what causes canker sores, whether they are the result of an allergy, a virus, an autoimmune condition, or all of these. They will often appear when people are feeling run down, have an injury or experience stress, or have a diet lacking in vitamin B12, folic acid, or iron. People who smoke also may experience canker sores more frequently. They can come back many times in a single year. 


This type of sore is usually small, oval or round, and grayish white. It is frequently surrounded by inflamed, reddish tissue. Canker sores can develop anywhere in the mouth, but usually people have them in their inner cheeks and lips, on their soft palate, tongue, or at the base of the gums. 

When a canker sore is developing, you may feel a tingling or burning sensation before you see it appear. Usually the sore will be painful for 3-4 days and then heal slowly over 10-15 days before it disappears.

Treatment of Canker Sores

Unfortunately, you can’t prevent canker sores or cure them. Treatments mostly focus on making them more bearable during the 3-4 days of painful discomfort and preventing them from getting infected. 

Avoid eating spicy or acidic food, and be careful to brush your teeth around the sores. You can use a numbing gel if you need relief from the pain. A wet tea bag held over the site of the sore can also help.

Gargling with mouthwash, hydrogen peroxide diluted with water, or a mix of saltwater and baking soda can promote faster healing. 

If you experience canker sores very frequently, you will want to talk to your doctor to see if you have a dietary deficiency, an allergic reaction to certain foods, or an autoimmune condition. You will also want to see a doctor if the sores are very large, last two weeks or more, are very painful, or you run a high fever when the sores appear.

In most cases canker sores will go away on their own after only a few days of usually mild pain. They are not life threatening, and they won’t damage your teeth or gums permanently. Talk to your dentist, though, if you have a dental condition or a dental appliance that irritates your mouth or seems to trigger canker sores. He can make recommendations for ways you can avoid further irritation.