canker sores for banner FORMATTED-648970758.jpg

What to Do for a Canker Sore

Posted by Paul O’Leary, M.D. on Jun 21, 2017 8:08:00 AM

Canker sores are painful, frustrating conditions that some people deal with over and over again. Let’s talk about what they are, what you should do if you have one and whether or not they can be prevented. 

A Canker Sore Primer

First, let’s address the terminology. Cold sores and canker sores are not the same thing, even though the terms are often (incorrectly) used interchangeably. Cold sores, or fever blisters, are caused by a virus, appear outside of the mouth – usually around the lips, near the chin or under the nose – and are contagious. Canker sores are sores inside of your mouth – typically inside the cheek, but they can also appear on the tongue or soft palate. These sores aren’t contagious, and they are often round in shape and are white or grayish with a red border. They are not caused by a virus like cold sores are; however, we’re not really sure exactly what causes them. Stress, previous injury to the area (such as accidentally biting the inside of your cheek), acidic foods (like lemons, oranges or pineapples), braces and even underlying health conditions like vitamin deficiencies or celiac disease have all been linked to canker sores.

canker sores upper lip-500367872.jpg

Treatment Options

While canker sores are quite painful, the pain usually subsides within a few days and the sore itself typically goes away on its own within a week. There are several over-the-counter medications that can be used to numb the pain in the area and potentially speed up the healing time, Talk with your doctor about which ones might work for you. 

If the sore is severe, there are some laser treatments, usually provided by your dentist, which can significantly reduce the pain and healing time. 

There are various home remedies you can find online to try and treat or numb the pain from a canker sore, but it’s best to contact your physician before attempting any of these.

canker sores meds-531825443 (1).jpg

Possible Ways to Prevent Them

Because we’re not entirely sure what causes canker sores, there isn’t a surefire way to stop them from happening, but there are some things physicians feel you can do that could aid in their prevention. 

  • Lower your stress and get plenty of rest.
  • Avoid biting the inside of your mouth or tongue. This means chewing carefully.
  • Avoid spicy or acidic foods. 

Usually, canker sores are nothing to worry about, but they can sometimes be associated with other health issues. If you’re noticing the following symptoms associated with your canker sore, notify your doctor: 

  • Sores that seem unusually large or are spreading
  • Canker sores that last longer than three weeks
  • Pain that seems intolerable or unavoidable, even when you cut out acidic or spicy foods
  • Problems getting enough fluid because of pain
  • A high fever 


Dr. Paul O’Leary is a board-certified Internal Medicine physician at Kelsey-Seybold’s Kingwood Clinic. His clinical interests include preventive healthcare, hypertension, lipid disorders and patient education.


Topics: canker sore, how to prevent a canker sore, canker sore treatment

New Call-to-action

Subscribe to Email Updates

Recent Posts

Posts by Topic

see all