Canker Sore: Causes, Types and 13 Proven Treatments

The pain and discomfort from a canker sore can make it difficult to eat or drink, and if you’re one of the many people who regularly cope with these sores, you know how important it is to be able to get relief when you need it.

Our guide helps you understand what causes canker sores, and how to treat them, both conventionally and naturally.

We’ll share all the best natural remedies for this oral disorder with you, so you can quickly heal and get back to enjoying life on your terms.

We’ll even share our best tips with you about preventing canker sores from forming, which can help you live pain-free in the future.

But first, we’ll uncover the facts about canker sores, including what causes them and their most common symptoms.

Understanding Canker Sores

Canker sores develop in the soft tissue located inside your cheeks, under your tongue, inside your lips, and at the base of your gums.

They are shallow, small, benign ulcers.

Other names for canker sores include aphthous ulcers and aphthous stomatitis.

So what do canker sores look like?

They’re usually oval or round, and they have a red border with a yellow or white center.

Canker sores are sometimes preceded by tingling or burning in your mouth.

They always form on the inside of your mouth, never the outside.

These types of sores aren’t contagious.

If you’ve ever had a canker sore, the chances are high that others in your family have them, too (1).

Women are also more likely to develop canker sores than men.

However, you can develop a canker sore at any age, even if you’ve never had one, so never think you’re immune to this unfortunate ailment.

At least one in five people have had a canker sore at some point in their lives.

Some people confuse canker cores with cold sores, which are also known as fever blisters.

Cold sores form outside of the mouth, usually on the lips, under the chin, or around the nose.

Meanwhile, canker sores only exist on the soft tissue inside your mouth.

While cankers aren’t contagious, cold sores are extremely contagious, because the herpes simplex type 1 virus causes them.

Cold sores are groups of blisters filled with fluid.

Each type of canker has its own symptoms. Below, we describe each type.

These descriptions will help you identify your canker sore, so you know the best way to treat it.

Types of Canker Sores

The most common type of canker sore is the minor canker sore.

Minor cankers have a red edge and are usually small and oval.

Minor canker sores can cause pain, especially while eating.

Minor cankers usually heal within one to two weeks, and they generally don’t scars.

Major canker sores are less common than their minor siblings.

As the name implies, they’re bigger, deeper, and more painful than minor sores.

Major cankers usually have defined borders and are round, but if they grow very large, their edges may become irregular.

These sores can take up to six weeks to heal, and many will leave a scar behind.

The final and least common type is known as a herpetiform canker sore, which usually occurs in the elderly.

While each canker is only the size of the head of a pin, they tend to grow in groups, which can vary between 10 to 100 sores when clumped together, and sometimes merge into one.

Herpetiform cankers usually take about one or two weeks to heal, and they don’t usually leave a scar.

• Other Symptoms of Canker Sores

While nearly all canker sores cause pain and discomfort, some can also lead to a fever, create swollen lymph nodes, or cause malaise (general uneasiness or discomfort).

Causes of Canker Sores

While there is no single, identified cause of canker sores, many factors can trigger a canker sore to form.

The following factors can contribute to the development of a new canker sore:

• Accidentally biting your cheek
• Food sensitivities, especially to gluten or acidic or spicy foods
• Injury from dental work
• Brushing teeth too forcefully
• Certain dental care products that contain sodium lauryl sulfate
• A change in hormone levels
• Emotional stress
• Deficiencies in certain vitamins and minerals, such as zinc, folic acid, iron, and B vitamins
• Some kinds of bacteria, especially H. pylori (which also causes gastric ulcers)

Some diseases can also spark the formation of canker sores, which include:

• HIV/AIDS
• Inflammatory bowel problems, such as Crohn’s disease and ulcerative colitis
• Celiac disease
• Behcet’s disease
• Other diseases that result in immune suppression or inflammation

While most canker sores are small and heal on their own within a week or so, living with pain and discomfort for that long can become tiresome and annoying, so learning how to treat canker sores is important for anyone who suffers from them.

There are ways to conventionally treat canker sores, and there are even more ways to naturally manage these painful ulcers.

Conventional Treatments

While minor canker sores require little treatment, major canker sores may necessitate intervention.

A few conventional treatments are specifically designed for canker sores.

If your canker sore doesn’t warrant a trip to the doctor, you can use over-the-counter liquids, gels, and creams to reduce pain and promote faster healing.

The most common ingredients in effective canker sore treatments include benzocaine, fluocinonide, and hydrogen peroxide.

Apply them to individual canker sores.

If you’re unsure which product will work best for your canker sore, check with your dentist or doctor.

Your doctor may choose to prescribe an oral steroid rinse to lower inflammation and reduce pain.

The most common ingredients in these mouthwashes are dexamethasone and lidocaine.

Your doctor may also choose to prescribe an oral medication that will help treat recurring canker sores.

Sucralfate and colchicine are both occasionally used to treat cankers, even though they were originally designed to treat other diseases.

If you have recurrent sores that don’t respond to other treatments, your doctor may also prescribe oral steroids.

A more invasive and extreme treatment for canker sores is cautery, which involves using a chemical or instrument to sear or burn the sore and destroy the tissue.

By burning the sore, you can actually promote faster healing.

The chemicals debacterol and silver nitrate are sometimes used to cauterize canker sores.

Natural Treatments

If you prefer to treat the pain and other symptoms of canker sores at home, we describe several natural treatments below that are effective and inexpensive and involve no harsh side effects.

Ice

Sucking on ice chips or small cubes can soothe the pain and inflammation associated with canker sores.

Ice and cold reduce blood flow, which lowers swelling and pain.

You can even freeze a wet washcloth, and place it on your canker sore.

Just be sure to use a clean washcloth each time.

B Vitamins

Nutritional deficiencies can sometimes cause canker sores, and the most common vitamin deficiency associated with cankers is Vitamin B12.

Even when people aren’t deficient in this nutrient, taking a B12 supplement has been shown to reduce symptoms in those who have canker sores (2).

If you have recurring cankers, try taking one thousand micrograms twice a day for six months, and see if your symptoms improve.

Other B Vitamins, such as B1 and B2, are also linked to canker-sore development.

A deficiency in Vitamin B1, also known as thiamine, can cause an increased risk for the development of canker sores.

To get all the B Vitamins you need, consider taking a B-Complex vitamin every day.

Zinc

A zinc deficiency can also cause canker sores.

Anyone deficient in zinc may find reduced recurrences and quicker healing when they take zinc supplements or use zinc lozenges.

To determine your current serum zinc levels and find out whether supplementation is right for you, talk with your doctor.

Iron

There is also a correlation between iron deficiencies and the development of canker sores (3).

Because taking too much iron can be just as unhealthy as an iron deficiency, you should have your blood tested first, in order to determine if you’re deficient in this nutrient before taking any supplements.

A blood test will also help determine the dosage you need to take.

Yogurt

The probiotics found in yogurt can promote healing and boost your immune system.

As you eat the yogurt, these helpful bacteria can help your canker sore heal, and by adding probiotics to your gut, you’re helping your immune system stay on track and internally fight the sore.

Yogurt is also cool and refreshing, which can additionally ease the pain.

Apple Cider Vinegar

The acetic acid found in apple cider vinegar is excellent for getting rid of the harmful bacteria that prevents healing, while also promoting the growth of helpful bacteria in your mouth.

Dilute apple cider vinegar with equal parts water, then gargle with it every day while you have a canker sore.

This action will significantly speed up your healing time.

Hydrogen Peroxide

To further reduce harmful bacteria and promote faster healing, use hydrogen peroxide.

Mix equal parts water and hydrogen peroxide, then directly apply a cotton swab to your canker sore.

After applying, refrain from eating or drinking for 60 minutes. Until your sore is healed, repeat this process daily.

Tea Bags

The tannin content in black tea has positive effects on canker sores.

To reduce pain and inflammation, brew a cup of tea by using a black tea bag, then take the wet teabag and place it directly on your sore.

As an anti-inflammatory, chamomile is also an effective treatment for canker sores, and you can follow the same procedure.

Aloe

Aloe vera can speed up healing, and it’s soothing, which you’ll need when you have a canker sore.

Start by slicing fresh aloe leaves to reveal the healing gel inside.

Use a cotton swab to dry your canker sore, then use another swab or spoon to place aloe directly on the wound.

Frequently repeat this action until your ulcer is healed.

It’s safe to swallow aloe vera gel, so don’t worry if some of it makes its way down your throat.

Coconut Oil

Coconut oil not only reduces inflammation but can also help eliminate the bacteria that cause some types of canker sores.

Swish warm coconut oil around in your mouth, especially focusing on the area that the canker sore is in.

Repeat this action several times a day.

You can also directly apply coconut oil to your canker sore.

Echinacea

Echinacea can help your wound heal quickly and simultaneously boost your immune system, both of which will help you quickly get rid of your canker sore.

You can add one teaspoon of liquid echinacea to one teaspoon of warm water, then swish it around in your mouth for two minutes.

You can either spit the mixture out or swallow it.

To help your canker sore heal more quickly, you can repeat this action up to three times per day.

Watermelon Frost

In China, an herb known as watermelon frost has been used to treat canker sores for centuries.

This herb is available as a spray, tablets, or a powder, and it should be directly applied to the canker sore to relieve pain and promote healing.

Be sure to purchase herbs online or from a reputable manufacturer, as some herbs from China and other Asian countries are known to carry high levels of contaminants.

Homemade Canker Sore Mouth Rinse

You can create your own mouth rinse, which can be very effective at treating canker sores.

The ingredients in this rinse are known to lower inflammation and reduce pain.

Combine one teaspoon of baking soda with two tablespoons of aloe vera juice and one-half cup of warm water.

Stir this mixture well until all the ingredients are well-blended.

Place a small amount in your mouth, swish it around for ten seconds, and spit it out.

Repeat until you’ve used all the rinse you made.

Repeat this process every day until your canker sore has completely healed.

How to Prevent a Canker Sore

It’s equally important to know how to treat a canker sore and prevent it from forming.

While these methods may not completely prevent all canker sores, they can greatly reduce their frequency and severity.

If you see any connection between canker-sore outbreaks and gluten, cut it from your diet.

If you’re concerned that you may be gluten-intolerant, talk to your doctor about getting tested for Celiac disease.

If you’re allergic or sensitive to gluten, it could be contributing to your canker-sore outbreaks.

By avoiding certain foods, you can lower your risk of developing a canker sore.

Some of the top culprits are spicy foods, acidic foods, and rough foods.

They all cause irritation in your mouth, which can lead to canker sores.

If you already have a canker sore, it’s best to avoid them as well, since they can cause you more pain.

Do not use oral-care products that contain sodium lauryl sulfate.

Research confirms that this compound can contribute to the formation and recurrence of canker sores (4).

If you get frequent canker sores, you should avoid chewing gum, as it irritates the soft tissue of your mouth.

Always brush your teeth after every meal by using a soft-bristled brush, and floss daily.

This practice will promote good oral hygiene and remove any bacteria or irritants that can lead to a canker sore.

When to Seek Medical Help

While most canker sores aren’t serious, there are times when you want to seek medical care.

Call your doctor if:

• You have a canker sore that’s accompanied by a headache, fever, diarrhea, or rash.
• Your canker sore lasts for more than two weeks, is unusually large, or extends past your lips.
• Your canker-sore outbreaks are frequent.
• You develop new canker sores before old ones have healed (which could be a sign of another problem).
• Your pain is so severe that it interferes with your ability to sleep, eat, or drink.

If you suspect that a sharp tooth or dental work may be leading to canker sores, talk with your dentist.

Conclusion

Canker sores are ulcers that develop on the soft tissue inside your mouth.

They aren’t contagious and usually require little or no treatment.

Most canker sores heal within one week.

Conventional treatments for canker sores include gels and creams, oral medications, and mouth rinses.

Natural remedies include ice, aloe vera, vitamin and mineral supplements, yogurt, hydrogen peroxide, apple cider vinegar, coconut oil, echinacea, teabags, and watermelon frost.