How To Tell Apart a Cold Sore and a Canker Sore

Any type of obvious facial blemish can be upsetting. If the blemish is actually a sore, it can be physically painful in addition to cosmetically unappealing. To find out how to remove a canker sore in a safe and efficient way, a proper diagnosis is the first step.

Canker sores can happen to anyone at any age. They are approximately 1cm or less and occur in the mouth. These are open sores that are typically painful and surrounded by a bright red area.

How To Tell Apart a Cold Sore and a Canker Sore
How To Tell Apart a Cold Sore and a Canker Sore

Around 20% of the population has had a canker sore at one point or another during their life. Although they are more likely to occur between the ages of 10 and 40, they can appear at any point in time. Thankfully, canker sores are not indicative of a serious, life-altering oral condition. Canker sores are likely to appear inside the lips or gums, but they can form on the tongue. The sores are generally yellow or gray with a red and sometimes swollen border around them

Who Gets Canker Sores?

Anybody can get canker sores. Those who have a family history of stomatitis are more likely to experience these types of sores as well as anyone who experiences chronic stress. Although canker sores are benign, healing can take weeks.

While the cause for canker sores is unknown, there are a few possible triggers. Vigorous tooth brushing has been linked to painful sores in the mouth as well as dental or orthodontic work. Acidic foods such as citrus fruit can make canker sores worse.

Minor vs. Major Canker Sores

Canker sores can come in different sizes with varying pain. Minor canker sores are generally small with a significantly smaller red area surrounding the white or gray middle. The sore itself is oval and they can heal in less time than major canker sores. Usually minor canker sores do not leave scarring inside the mouth.

Major canker sores are both larger and deeper than minor canker sores. The red edges surrounding a white area can be irregularly shaped. Although the shape of a major canker sore can be less defined than a minor one, it is generally much more round than the oval-shaped minor canker sore. Major canker sores can be quite painful and can distract from regular daily activities. It takes much longer for a major canker sore to heal and it frequently leaves scarring.

Are Canker Sores and Cold Sores the Same?

Canker sores and cold sores are not the same. Cold sores are caused by the HSV-1 strain of the herpes simplex virus. This is a viral infection.

Canker sores are not contagious, but cold sores can be spread through oral contact. Unlike canker sores, cold sores usually appear on the outside of the mouth with the most likely place being on the lips. Cold sores are blister-like lesions that can cause pain if untreated.

Cold sores, while unfortunately very contagious, can clear up in as little as one week without treatment. Canker sores can take much longer to heal.

How to Tell If It’s A Canker Sore Or A Cold Sore

Oral health is extremely important for everyone. Knowing whether you have a canker sore or a cold sore can also be valuable for those around you. While canker sores are not contagious, cold sores can be contracted through kissing.

If you have a cold sore, there may be a cluster of blisters that appear around the mouth. They are first clear, but often become cloudy. For those who have recently acquired the HSV-1 strain of herpes, cold sore infections may be more severe.

A cold sore usually starts off feeling tingly. Over time there may be a burning sensation followed by painful sores around the mouth. In some cases, cold sores can appear on the nose or other areas of the face. Other symptoms of the virus that causes these cold sores includes sore throat, body aches, nausea or swollen lymph nodes. These do not have to occur for a cold sore to be present, but can be an indicator that the virus has been contracted.

Cold sores tend to come and go. Since the HSV-1 strain of herpes cannot be cured, outbreaks appear and disappear at various points in time.

Canker sores are identified in several different ways. The location of a canker sore is usually inside the mouth. Gums, below the tongue, the roof of the mouth and inside cheeks or lips are the primary areas where canker sores form.

Canker sores are frequently painful. Burning and tingling will usually occur before a canker sore is present. Unlike cold sore blisters, canker sores have either a round or oval shape and are either white, yellow or gray. Around the sore is a red border that can have distinct edges.

Unlike cold sores, canker sores can greatly vary in size. The larger a canker sore is, the more painful they are to manage. You can also tell the difference between a canker sore and a cold sore by how long they take to heal. Canker sores, unlike cold sores, can take weeks to heal on their own.

Corrective surgery can help heal painful oral health problems. Because mouth ulcers are not located in an area that is easy to heal, canker sores can require specialized treatment. For sores that need focused attention, laser treatment is a very effective option.


For people in the New York area who suffer from painful oral health issues, Dr. Marc Lazare performs safe and effective oral care. In addition to treating stars like Liza Minnelli, Dr. Lazare is a renowned lecturer and dental columnist with many years worth of experience. He started the Teeth Whitening Division at North Shore University Hospital and is president and founder of Cosmetic Innovations inc. Keeping up with new dental research and training, Dr. Marc Lazare is consistently competent at providing top-notch care. To set up an appointment for an initial consultation, please email the office of Dr. Marc Lazare.

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Thanks for stopping by today, I hope you’ve enjoyed this post.

rachel bustin

Thank you for sharing

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