Canker Sore on Tongue: Causes and How to Get Rid of It Naturally

Canker Sore on Tongue: Causes and How to Get Rid of It Naturally

A canker sore on the tongue is a small, round, painful ulcer with a white or yellow centre and a red border. It can sit on the tip, the side or under the tongue, and because your tongue never stops moving, it often hurts more than a canker sore anywhere else in the mouth. Most canker sores heal on their own within one to two weeks. You can ease the pain and speed things up with a few simple natural remedies. But if they keep coming back, the real answer usually lies in what’s going on inside your body, not on your tongue.

What Does a Canker Sore on the Tongue Look Like?

Canker sores, also called aphthous ulcers, are described by the American Dental Association as small, creamy white ulcers with a red border that are quite painful. They’re very common, and they are not contagious, so you can’t pass one on by kissing or sharing a cup. They always form inside the mouth, never on the outside of the lip. A blister on the outer lip is more likely a cold sore, which is a different thing entirely. Here’s how to tell a cold sore or a canker sore apart.

Researchers describe the ulcer as having a yellowish white base framed by a red halo. It doesn’t start as a blister. The tissue simply breaks down into an open sore, which exposes nerve endings, and that’s why it stings so much when you eat or talk.

Canker sore on the tip of the tongue

The tip of the tongue touches your teeth constantly, so sores here often follow a small bite or a scrape from a sharp tooth edge. They’re usually small but very noticeable, especially when you eat.

Canker sore on the side of the tongue

The side of the tongue rubs against your back teeth all day. A broken tooth, a rough filling or braces can keep irritating the same spot, so a canker sore on the side of the tongue can take longer to heal. If the same spot keeps getting sore, ask your dentist to check for a sharp edge.

Canker sore under the tongue

The soft skin under the tongue is thin and sensitive, which makes canker sores underneath the tongue some of the most painful. Swallowing and talking move this area constantly, so keeping it clean and calm matters here.

Canker sores can also appear on the gums, inside the cheek, on the inner lip and on the roof of the mouth. We cover those spots, including canker sores on the gums, in our main canker sore guide.

What Causes a Canker Sore on the Tongue?

Science still doesn’t have one clear answer. The American Dental Association says the exact cause is uncertain, and that an immune reaction may be involved, with fatigue, stress and allergies making them more likely. A 1991 paper found that canker sores tend to appear where the mouth has been injured, and that certain foods, including gluten in people with coeliac disease, can trigger them.

My view: an imbalance your body can’t fully fight off

From what I’ve seen, most canker sores come from an imbalance of bacteria or fungus in the body. Your system can’t fully battle it, so it comes out as an ulcer in the mouth.

The research is starting to point in a similar direction. An analysis of 14 studies found that people with canker sores have a different mix of mouth bacteria than people without them. The authors don’t blame one single germ. They suggest that the way these microbes interact may change the immune response or damage the lining of the mouth. Another study concluded that oral bacteria may play a significant role in how canker sores develop. The American Dental Association also notes that mouth sores in general can be caused by bacterial, viral or fungal infections. A thick white coating on the tongue can point to oral thrush, a yeast infection, which is worth getting checked.

This is also why doctors sometimes prescribe antibiotic mouth rinses for canker sores. For people who prefer a natural approach, that’s usually far too strong a way to tackle a small sore. It wipes out good bacteria along with the bad, and it doesn’t touch the reason the balance tipped in the first place.

Other common triggers

• Biting your tongue, a sharp tooth, braces or a rough filling
• Stress and tiredness
• Toothpaste with sodium lauryl sulfate (SLS), the ingredient that makes it foam
• Low vitamin B12, iron or folate
• Hormonal changes, such as around your period
• Certain foods, including very acidic or spicy food, and gluten in people who are sensitive to it

First Step for Recurring Canker Sores: Diagnose Your Lifestyle

If canker sores on your tongue are a common problem for you, don’t start with a cream. Start by looking honestly at your lifestyle. Too much alcohol, bread or sugar can push your system into an unregulated state where bacteria and yeast get the upper hand and your body struggles to keep up.

There’s research behind the bread part: studies have found gluten sensitivity in people with recurring canker sores, and for them, cutting gluten can make a real difference. The sugar and alcohol part is what I see again and again.

A detox from these common triggers might be your first step to avoiding mouth sores:

1. Cut back on sugar, including sweets, soft drinks and white bread.
2. Take a break from alcohol for a few weeks.
3. Cut down on bread and other gluten foods and see if your sores calm down.
4. Eat more vegetables, protein and fermented foods like plain yogurt to support healthy bacteria.
5. Keep a simple diary of what you ate in the days before a new sore appears.

How to Get Rid of a Canker Sore on the Tongue Naturally

1. Oil pulling with coconut oil

Oil pulling helps rebalance the bacteria in your mouth. Swish a tablespoon of coconut oil around your mouth for 10 to 15 minutes, then spit it into the bin (not the sink, it can clog pipes) and rinse with water. In one study, coconut oil pulling reduced harmful mouth bacteria about as well as a chlorhexidine mouthwash, without side effects. Do it every morning before brushing, during an outbreak and as a daily habit if you get sores often.

2. Apple cider vinegar and baking soda shot

If you’d like to tackle fungal overgrowth quickly, this is what I recommend: a small morning shot of apple cider vinegar mixed with a pinch of baking soda. In my experience it works fast. Make sure you have something else afterwards, like water or a cup of herbal tea, to rinse away the bad taste. Keep it diluted in water, since vinegar is acidic and can sting an open sore and wear down tooth enamel, and skip it if you have acid reflux. This is a personal and traditional remedy, not one that’s been studied for canker sores.

3. Raw honey

Honey has one of the best studies behind it. In a trial comparing honey with a steroid cream and a protective paste, honey shrank canker sores and reduced pain and redness faster than both, with no side effects. Dab a little raw or manuka honey on the sore after meals and before bed.

4. Salt water or baking soda rinse

A warm salt water rinse (half a teaspoon of salt in a glass of warm water) or a baking soda rinse (one teaspoon in half a glass of water) cleans the sore and calms the area. These are traditional remedies rather than well studied ones, but they’re gentle and cheap. Swish for 30 seconds and spit, three or four times a day.

5. Switch to an SLS free toothpaste

Sodium lauryl sulfate is the foaming ingredient in most toothpastes. A review of the trials found limited evidence that switching to an SLS free toothpaste helps people who get canker sores often. It’s an easy change worth trying.

6. Vitamin B12

In a double blind trial, people who took vitamin B12 every night for six months had fewer and less painful canker sores, and 74% reached a point with no sores at all, compared with 32% on a placebo. It worked even in people whose B12 levels were normal.

7. A gentle detox, alongside your diet changes

If you’d prefer something less invasive than the vinegar shot, you can use a zeolite detox spray, in addition to the dietary changes above, of course. Zeolite is a natural mineral that’s used to bind toxins. It hasn’t been studied for canker sores specifically, so see it as support for the bigger lifestyle reset, not a quick fix.

For more remedies, and a comparison with what you’ll find at the pharmacy, see our guide to canker sore treatment, which also covers canker sore remedies over the counter.

Comfort Care While It Heals

• Avoid hot, spicy, salty and acidic foods, as the American Dental Association advises, including crisps, citrus, tomatoes and vinegar dressings.
• Choose soft, cool foods like yogurt, oatmeal, bananas and smoothies.
• Drink through a straw to keep drinks off the sore.
• Brush gently with a soft brush, and take care around the sore.
• Don’t poke or pop it. It isn’t a blister, and touching it only irritates it.
• Stay hydrated, which helps the mouth lining heal.

How Long Does a Canker Sore on the Tongue Last?

Most small canker sores heal in one to two weeks, and the pain usually eases after the first three or four days. Larger ones can take several weeks and may leave a small scar. Sores on the side of the tongue sometimes take longer because they keep rubbing against the teeth.

Canker Sore or Something Else?

Not every sore on the tongue is a canker sore. Small red or white bumps on the tongue are often inflamed taste buds. See what a pimple in your mouth can mean. A generally sore, burning tongue without an ulcer has other causes, covered in causes of a sore tongue. And if you get sores in several places across your mouth, our guide to mouth ulcers is a good next read.

When to See a Dentist or Doctor

• A sore that hasn’t healed in three weeks, especially on the side of the tongue. See a dentist soon. Most are harmless, but a sore that doesn’t heal needs to be checked properly.
• Canker sores that keep coming back. Ask your GP for a blood test for vitamin B12, iron and folate.
• Sores together with bloating, diarrhoea or weight loss. A gastroenterologist can check for coeliac disease or other gut conditions.
• Very large sores, many sores at once, fever, or trouble eating and drinking. See a dentist or an oral medicine specialist.
• A thick white coating on the tongue that wipes off to leave a red patch. This can be oral thrush, so see your dentist or GP.

Knowing exactly what you’re dealing with is what lets you treat it the right way naturally.

Frequently Asked Questions

How do you get rid of a canker sore on your tongue fast?

Dab raw honey on it several times a day, rinse with salt water, avoid spicy and acidic food, and switch to an SLS free toothpaste. Oil pulling with coconut oil each morning helps rebalance the bacteria in your mouth.

Why do I keep getting canker sores on my tongue?

Often it’s an imbalance your body can’t fully fight off, pushed along by too much sugar, alcohol or bread, stress, or low vitamin B12. A sharp tooth that keeps catching the same spot is another common reason.

Are canker sores on the tongue contagious?

No. Canker sores aren’t caused by a virus you can pass on, so kissing or sharing drinks won’t spread them.

How long does a canker sore under the tongue last?

Usually one to two weeks. The pain often eases after three or four days.

Can a canker sore on the tongue be something serious?

Almost always it’s harmless. But any sore on the tongue that hasn’t healed within three weeks should be checked by a dentist.

This article is for general information and does not replace a diagnosis. If a sore doesn’t heal, keeps coming back or you feel unwell, see a dentist or doctor.

Veronique Cleas D'erckenteel

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