Fact Checked

Can You Pop a Canker Sore?

Written by Fernanda Elizalde

January 19, 2023

Medically Reviewed

By Dr. Greg Grillo, DDS

A canker sore is a small, painful ulcer that appears inside the mouth or on the tongue.

They are not contagious and the cause is not fully understood, but they can be triggered by stress, injury, certain foods, or certain medical conditions.

They typically heal on their own within 1-2 weeks. These painful sores are different from fever blisters, which are another type of severe mouth sores. But can you pop a canker sore? Yes and no. 

can you pop a canker sore? what do they look like?

What Do Canker Sores Look Like?

Most canker sores are small red, raw spots that are less than a quarter inch in diameter, although they can vary in size.

As these mouth ulcers "age," they typically develop a white-colored filmy cover over the top of the raw skin. A canker sore is usually a round or oval-shaped ulcer with a red border and a yellow or white center. 

Where Can a Canker Sore Appear?

A canker sore can appear almost anywhere inside the mouth, including on the tongue, palate, floor of the mouth, or on the inside of the lip or cheeks. They are usually painful enough that they can interfere with eating or drinking.

Many people ask, "Can you pop a canker sore" simply to speed up the canker sore healing process. Unfortunately, these "aphthous ulcers" don't exactly work like that. 

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Causes of Canker Sores

There is not one specific cause of canker sores, but we do know that there are a number of factors that may contribute to their development. These include:

Injuries to the mouth: Canker sores can be caused by accidental bites, burns, or other injuries to the inside of the mouth, including irritation caused by orthodontic appliances.

Hormonal changes: Some people may be more likely to develop canker sores during times of hormonal changes, such as during menses or pregnancy.

Nutritional deficiencies: A lack of certain nutrients, including iron, folic acid, or vitamin B12, may increase the risk of canker sores.

Allergic reactions: Ingredients such as sodium lauryl sulfate, which is found in many kinds of toothpaste, can cause mouth sores or peeling skin.

Certain medical conditions: People with known medical conditions, such as celiac disease or inflammatory bowel disease, or even acid reflux, may be more prone to canker sores.

Bacterial or viral infections: Some canker sores may be caused by bacteria or certain viruses.

Stress: High levels of stress can also be a trigger for canker sores, as it strains our immune system.

Spicy or acidic foods: Some people may be more prone to canker sores when they eat certain foods, such as chocolate, coffee, acidic fruits such as orange juice or lemons, or spicy foods.

How To Get Rid Of A Canker Sore Fast

The natural recovery process for canker sores is usually 10-14 days. Severe canker sores won't heal overnight, even with the best home remedies.

However, there are some things you can do to ease the pain of your mouth ulcer and reduce inflammation. Such as creating a "miracle" mouth rinse with magnesia milk or dabbing it directly onto your canker sore with a cotton swab.

Always be sure to avoid mouthwash with alcohol, as this can increase your discomfort if you have mouth sores. Some people also prefer a warm water and baking soda rinse, swishing with salt water, or applying aloe juice. 

It's important that you avoid irritating complex canker sores, as it may slow the healing process. If your canker sores do not heal within two weeks, you'll want to seek out medical help from your doctor or dentist. Delayed healing time could indicate something more severe than a traditional canker sore. 


What's inside a canker sore?

Sometimes a canker sore will have a small blister over the top of it, where white blood cells have rushed in because of anti-inflammatory properties found in our immune system. Even though you do not want to purposely pop a canker sore, it will pop on its own at some point. 

Small ulcers like canker sores are typically shallow white because of the raw, irritated tissues on the surface. If there is a blister over the canker sore in the early stages of flare-ups, it's usually filled with white blood cells and antibodies.

Most will leave open wounds rather than create small pimples on your skin, which is more common with a cold sore. And unlike cold sores, a canker sore does not contain a virus or cause a tingling or burning sensation when it starts to flare up. 

How can I get rid of canker sores quickly?

The best way to get rid of any canker sore is to avoid irritation to that site and allow natural healing to take place.

You can't speed up healing time, but you can address the discomfort throughout the process. Some of the things that may provide relief are placing a tea bag onto the swollen area, rinsing with warm salt water, or using over-the-counter pain medication as directed. 

Some dentists also offer laser treatments for managing painful sores like aphthous ulcers and fever blisters. The key is to see your doctor as early as possible. Laser therapy can cut healing times in half, providing exceptional results over most home remedies.

Are canker sores contagious?

Unlike cold sores that typically develop on and around the lips, canker sores can't spread by kissing or sharing food. However, fever blisters or "cold sores" are viral in nature, so those types of mouth sores will spread viruses from one person to the next during episodes of flare-ups. 

Why do I keep getting canker sores?

If you repeatedly develop a canker sore in the same area of your mouth over and over, it's important to discuss this issue with your dentist.

It could be that there is an issue such as an orthodontic wire, a filling fell out, or you have a broken tooth that is constantly irritating that area of your mouth. Professional treatment, such as restoring your tooth or adjusting your orthodontic appliances, may be necessary. If you're currently in braces, one of the best home remedies for extremely painful mouth ulcers is to apply orthodontic wax over the brackets or wires in that space. 

Also, be sure to monitor your diet and existing health conditions, such as acid reflux disease, as these could be contributing to how often you get mouth sores. 

You can't heal a canker sore overnight, but identifying the cause of your pain and discomfort will help prevent recurring flare-ups. 

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Know When to See Your Dentist

Any sore that does not heal within 10-14 days could be something more serious, such as an abscessed tooth, precancerous tissue, or a more severe type of skin lesion.

Dentists can also prescribe medications for recurring mouth ulcers or use laser therapy to speed healing times when applicable.

If you’re not already, plan to schedule an exam and oral cancer screening with your dentist every six months to keep your smile as healthy as possible.