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How to Get Rid of Canker Sores (Mouth Ulcers)

Written By: Margaret Boyles Contributor

Ever had a canker sore? A type of mouth ulcer, these shallow white lesions are small and can appear anywhere inside the mouth, including the gums, tongue, and inside of the lips.  They can make eating and drinking mighty uncomfortable for a week or more. Here’s how to relieve canker sores.

What are Canker Sores?

Canker sores are whitish, red-bordered, slightly-cratered sores inside the mouth. Medical science knows that these commonly occurring sores by the somewhat frightening names, aphthous stomatitis, or aphthous ulcers. Women are more susceptible to canker sores than men, and some people seem more likely to get them than others.

The good news: unlike cold sores*, they aren’t infectious, so you can’t spread them to others or to other parts of your own body.

What Causes Canker Sores?

Brought on by stress, allergies, gluten sensitivity, hormonal changes, injury to the mouth, dental work, vitamin or mineral deficiencies, or—most commonly—unknown causes, canker sores typically heal without treatment within a week or two.

But experts recommend consulting your healthcare professional if:

  • A canker sore bleeds, oozes, or crusts over.
  • You experience fever or severe, long-lasting pain.
  • Your canker sore is unusually large and persistent.
  • You suffer frequently recurring canker sores, which may suggest an underlying disease.

How to Prevent Canker Sores

To help prevent recurrent canker sores, healthcare professionals suggest:

  • Avoiding toothpastes containing sodium lauryl sulfate.
  • Reflecting on what trigger foods or drinks might be the culprit. Common triggers: walnuts, strawberries, eggs, cheese, chocolate, spicy foods.
  • Consulting your orthodontist if sharp edges on braces, dental retainers, or other dental appliances irritate your mouth.

Canker Sore Remedies

You can choose from a variety of prescription and over-the-counter products to soothe the pain and accelerate healing. I suffered a series of painful canker sores last winter, before discovering my increased intake of walnuts as the culprit.

My favorite natural remedy: a soothing cup of warm sage/chamomile tea, swooshing it around as a mouthwash while I sipped.

Another remedy is to simply rinse your mouth with baking soda (dissolve 1 teaspoon of baking soda in 1/2 cup warm water).

It also can help to blot your sores with milk of magnesia a few times a day.

To find relief from pain, let some ice chips dissolve in your mouth.
Also, be sure to use a very soft toothbrush and try a sensitive toothpaste, nothing abrasive.

* Don’t confuse canker sores with cold sores. Cold sores (“fever blisters”), caused by the herpes simplex virus, occur on the outside of the mouth, typically on or around the lips. Often brought on by stress or hormonal changes, they appear as red, painful, fluid-filled blisters that are highly contagious. See how to treat cold sores!

Natural Remedies

About The Author

Margaret Boyles

Margaret Boyles

Contributor

Margaret Boyles is a longtime contributor to The Old Farmer's Almanac. he wrote for UNH Cooperative Extension, managed NH Outside (a writing collaborative for Extension natural resources volunteers), ...

Read more from Margaret Boyles

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Comments

<span>Sabrina Nicholson</span> Fri, 10/30/2015 - 18:06
I used to get them as a kid every once in a while at my grandparents house (don't ask). Anyway, my grandpa would always put a daub of Campho-phenique on them. Stung for a second, but then it numbed it and went away. It came in a little green bottle. I don't know if they still make it, but it sure worked!
<span>A W</span> Wed, 09/07/2022 - 16:22
In case anyone else goes searching the Internet for this, I second this method for dealing with a canker sore inside your mouth. Now Campho Phenique is not to be ingested so always, always rinse your mouth afterwards. Their website says not to use this inside the mouth but we always did as kids. It was our family's go to method for healing up canker sores fast! Take a qtip, dip in Campho Phenique, apply to canker sore until numb, then rinse mouth liberally with water. This stuff is toxic when ingested but fine when used responsibly.
<span>Jack Duquesne</span> Fri, 10/30/2015 - 16:38
L-lysine will clear it up really quick. Lysine is an amino acid that protects your mouth and helps to create healthy saliva. Take around 5000mg and once again before bed! Works like a charm.
<a rel="nofollow" href="https://www.facebook.com/roger.young.399">Rogeragain</a> Fri, 10/30/2015 - 07:26
Just so I make myself clear I should of been the poster boy for this ....And now I truly believe Vitamin D is the cure for it..If you you are suffering from constant outbreaks like I was "GO SEE YOUR DOCTOR" get your vitamin levels checked. These sores are not natural like most people treat them ...there is a cause, And there is most likely is a treatment.
<a rel="nofollow" href="https://www.facebook.com/roger.young.399">Roger</a> Fri, 10/30/2015 - 07:14
Well I suffered for 3-4 years with this ..constant outbreaks with canker sores, was hard to even eat was so bad .. until I had enough and went to my doctor ....found out low vitamin D can cause this, and after blood work to check vitamin level's my vitamin D was extremely low... so low in fact my doctor had never seen it that low . He said probably in simple terms so I could understand what the numbers meant that my Vitamin D level was 2-3 out of 10. I take vitamin D every day and the sores are history. So just take vitamin D and get a blood test done .
<span>L Howe</span> Thu, 10/29/2015 - 23:36
The best preventative we found is the toothpaste without sodium laurel sulfate, but they still pop up on occasion. I had a dentist once tell me to use cotton soaked with vitamin e, maybe that would work for others.
<span>Terri Little</span> Thu, 10/29/2015 - 22:44
Adults: 500 mg l-lysine and 1 capsule probiotic 3 times a day with 8 oz water. Child-under 12: 250mg l-lysine and 1 capsule probiotic 3 times a day (if the child is under 5 crush and put in applesauce or yogurt) The sores will be gone within 24 hours. L-lysine and the probiotic can be found anywhere-Walmart, Dollar General, Dollar Tree, anywhere that sells vitamins. You will be amazed at how quickly and effectively that this works.
<span>Terri Little</span> Thu, 10/29/2015 - 22:40
Adults: 500 mg l-lysine and 1 capsule probiotic 3 times a day with 8 oz water. Child-under 12: 250mg l-lysine and 1 capsule probiotic 3 times a day (if the child is under 5 crush and put in applesauce or yogurt) The sores will be gone within 24 hours. L-lysine and the probiotic can be found anywhere-Walmart, Dollar General, Dollar Tree, anywhere that sells vitamins. You will be amazed at how quickly and effectively that this works.
<span>Joe Morris</span> Thu, 10/29/2015 - 22:04
you can also swish hydrogen peroxide for a few min a couple of times a day
<span>G K Alexander</span> Fri, 10/30/2015 - 00:33
I agree with Joe, I recently started some new medications and one caused blisters (Canker Sores)in my mouth and on my tongue, until I swished with hydrogen peroxide did I find something that actually worked and I immediately felt better (I tried several different mouth washes). When they started to hurt I would swish again (every couple of hours) with hydrogen peroxide by the next day I felt much better and by the third day they were gone.