Open mouth with canker sore on inner lip

Canker Sores: Causes and How to Treat Them

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Anyone that suffers from canker sores knows that they can strike anytime. They also cause a lot of pain and discomfort in your mouth, keeping you from having a smile on your face. You may not even know what may have triggered it, which can also be frustrating.

All you can think about is that obnoxious sore in your mouth. There’s a number of ways that you can help soothe the pain. Here’s information about canker sores, on what causes them, and how you can treat them. 

Basic Info on Canker Sores

The correct term for canker sores is aphthous ulcers or aphthous stomatitis. They are little painful ulcers that can happen anywhere in the mouth, including your throat, tongue, lips and inside lining of your cheeks.

They can also show up in a gray, white, or yellow color, surrounded by a red color. It’s also not uncommon for there to be more than one in your mouth at the same time. 

Canker sores are different from cold sores and cannot be spread to other people. Cold sores also typically show up on the outside of the mouth, while canker sores are found on the inside.

These types of sores are more common in women than men, yet teens and young adults can get them too. The tendency to get canker sores can be inherited down through the family.  

Types of Sores   

Minor Sores

Minor sores are the most common type and can measure from 3 to 10 mm. They usually last for around 10 to 14 days and will not leave any scarring. 

Major Sores

Major sores are much larger and deeper, with a ring larger than 10 mm. They also will take between 2 weeks and several months to heal and could leave a scar afterward. 

Herpetiform Sores 

You could have multiple groups of herpetiform sores in your mouth at one time. They are usually between 2 and 3 mm in size but you could experience as many as 100 of them at one time. Like the minor sores, herpetiform sores should heal without any scarring. 

Symptoms of Canker Sores

The most common symptoms of canker sores include a tingly or burning sensation up to 24 hours before the ulcers first appear.

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You’ll also feel a painful sore in your mouth and could have trouble eating, talking, or swallowing. The ulcers will be white, grey, or yellow, with a red border around it.  

Causes of Canker Sores

There are many factors that could be at play that’s causing your canker sores. Some of these include an injury to your mouth, food allergies, smoking, cold, flu, stress, or even oral cancer. 

There are several types of prescription drugs that you may be taking that could be causing them. Some people have indicated the sores cleared up and didn’t return when they changed the brand of toothpaste they used. If you have canker sores you may want to try a new brand at your house.

Treatment for Canker Sores

For the most part, canker sores will heal on their own, needing no treatment on your part whatsoever. However, if you are experiencing pain that won’t go away, there are a few things that you can try.

There are several home remedies that you can use around the house to help relieve the pain. 

You can allow ice chips to melt in your mouth to help relieve the pain. Make sure that you are using a toothbrush that has soft bristles. Rinsing your mouth with warm salt water will also help.

Applying milk of magnesia with a cotton swab might also help relieve the pain caused by the sore. The herb echinacea can also help with healing the sore quicker.

It’s also important that you chew carefully when you’re trying to eat around these sores. If your teeth bite down on the tissue, it’s not only going to hurt, but also causes them to stick around longer.

You also need to find a way to relax if you believe that stress may be a factor in what has caused the canker sores.   

Mouthwashes for Sores 

There are a number of mouthwashes that will help relieve the pain in your mouth. Diphenhydramine suspension is an over the counter mouthwash that works on the mouth tissue as an anesthetic.

Go ahead and put the suspension in your mouth and swish it around for 30 seconds to a minute. Make sure that you spit it out without swallowing it.

You also may need to have an anti-inflammatory steroid prescribed to you by a doctor to help with the inflammation. Then there’s also Tetracycline antibiotic rinses that can help with the pain and help with the healing of the sores.

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These are also prescribed by a doctor and are not to be taken by young people under the age of 16, or if you are pregnant. 

Oral Medications 

There are several oral medications that you can take that will help fight against canker sores. Over the counter pain medication such as Advil, Tylenol, Aleve, and Ibuprofen can help with the discomfort.

You may also be dealing with a vitamin deficiency that’s causing the sores. Taking vitamins B and C might also help with the symptoms.   

When to Call Your Doctor

Under normal circumstances, canker sores should heal without any need to go to the doctor. If, however, you notice that the sores are larger than normal or that they are spreading and hanging around longer than 3 weeks, you need to get ahold of your doctor.

If you happen to catch a fever at the same time or are having difficulty staying hydrated, these are other areas of concern. 

If you suffer from canker sores that keep returning and you know it’s not genetic, you might want to get checked out by a doctor. In some cases, it could be signs of Crohn’s disease, lupus, celiac disease, or even aids or HIV. 

When All Else Fails

My husband, Mark used to get mouth cankers all the time. A friend of ours who was a nurse at a local clinic up in Salt Lake City, Utah told him to try switching his brand of toothpaste.

We had been using the same brand for years. She said some of her patients/clients switched from their usual brand to Colgate and their canker sores went away. Mark switched toothpaste and he has never had a canker since switching to Colgate. Mark suggested the same thing to a business associate years ago. He reported back that his sores had gone away too.

We mentioned this to our dentist of ten years and now he hands out only Colgate tubes to his clients. Is there any scientific research here, no there is not. Just plain commonsense, we learned on a fluke.

Final Word

Canker sores can be such a pain. You’ll be focused on it all day because of the obnoxious space that it’s taking over in your mouth. Hopefully these causes and ways to treat them have helped you be better informed on how to ease the pain and clear up the sores too.

Are you a person that suffers from canker sores from time to time? Stay safe, stay well, my friends. May God bless this world, Linda

Natural Remedies by Linda

Pink Eye by Linda

Copyright images: Canker Sores AdobeStock_114353331

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  1. I used to get canker sores in the summer when i would eat a lot of tomatoes. The acid in them was a problem for me. I would put salt on the sore and it would go away in a day or two. Straight salt does burn a bit but it works. Almost instant relief.
    If i had more than one sore I rinsed my mouth with salt water. It worked every time and worked fast. Don’t swallow the water.
    Now with tomatoes not so acidic i no longer have that problem.

  2. I used to get canker sores a lot and learned to hold a zinc tablet between the sore and my lip or teeth, depending on the location. I would keep it there until it began to dissolve, then rinse it down with water. It usually went away within the day and much less sore in the meantime. The healing had already begun!

    1. If you have a canker sore, do this. Take a fruit flavored tums. Place in your mouth against the sore. Let it sit there and carefully dissolve. Do not talk while doing this, do not chew or move the tablet with your tongue. Takes a few minutes. Then take another fruit flavored tums and do the same thing. This will make things much better.

  3. My husband used to get canker sores. He put powdered Alum right on the sore. He says it dried them right up. He doesn’t get them any more.

  4. My grandson gets them constantly and yes they are very painful. He started getting them at about age 10 and at 14 he would get one as soon as the other had healed. His pediatrician said it was just going through puberty. (I remember getting them as a teen as well but not since then. ) We have tried alum, anbesol, a mouthwash for mouth sores, all kinds of “apply with a q-tip” things and nothing has really helped. He is so miserable sometimes that he can’t eat because he will get 3 or 4 at one time. Drs really seem to not care or think its not a big deal but when you are that miserable it is a big deal. I will try changing the tooth paste and the zinc as well. (The only medications he takes is a high blood pressure pill twice a day that is used off label for migraine.)

    1. Hi Stephanie, that is terrible that he’s had them so many years. My husband used to have to get them cauterized. THEN we learned about Colgate. We were desperate. They went away within a week or so. He has never gotten any since. I sure hope you find out what is causing his. Linda

      1. Thank you Linda, we have used many toothpastes as I am a “sale” person and buy what is cheapest but I don’t think we ever used Colgate. I’m getting some today for him. Thank you so much for this suggestion.

    2. B12! My friend recommended that I may have a deficiency. Oh my gosh! It saved me! I used Vimergy B12 drops, Mary Ruth makes a spray that is much more palatable for children.
      Good luck! Cankers are miserable!

  5. I have bitten my lips and scratched the inside of my gums so many times. I never touch the spot, but now I wonder if they were canker sores. In any case, I rinsed, drank cold liquids and just waited for it to heal. I usually caused it myself, by biting or scratching mishaps, otherwise, a few times I had a taste bud pop and had a cavity or something, but of course I had that looked at and taken care of by a dentist.

  6. Just this week a large painful canker sore appeared on my lower lip. I’ve had small canker ulcers before as a result of lupus and some medications. Never have had one near my mouth or so large. I am a true believer in the use of essential oils so I did some research and decided to apply TEA TREE oil directly on the sore for one minute. To my very welcome surprise the pain was gone and the ulcerated area started to heal. I repeated this a few times a day and in 2 days it is almost completely healed.

  7. For outside sores, I use Abreva, but whenever I get sores inside or outside my mouth, I stop taking chocolate, orange/grapefruit juice, and sugar. I start eating white foods like milk, potatoes, limas, etc… I take vitamin C. Most important is I take Lysine found in the vitamin section. If it’s really bothering me, I hold it against the spot with my tongue where it’s bothering me and it heals up within a day. I heard that Lysine helps with shingles too since they are caused by similar viruses.

  8. After years of having canker sores and trying numerous remedies which never helped much, I realized what was the cause of my sores. I would get canker sores when I drank too much soda pop, orange juice, etc, drinks that had a lot of acid in them. I found that taking 1/2 tsp of baking soda, well mixed in a half a glass of water, a couple times a day would alleviate my sores in a few days. Now, if I drink a lot of pop or o.j., for whatever the reason, I will take the baking soda afterwards and prevent the little buggers from even starting.

  9. I have gotten both the exterior lip sores and interior cankers over the years- my exterior lip sores are caused by sun exposure, and abreva used right away has helped, and of course sun screen directly on the lips before going out in the sun. For the interior ones, I right away rinse with salt water and/or peroxide, which tends to stop the progression and start healing- and if they have gotten large and painful, the BEST thing is spraying Chloraseptic on it, just before eating or when the pain is bad. It is an over-the-counter sore throat spray that has an anesthetic in it that works immediately- the green one is the best, not the orange one.

  10. I used to get canker sores quite frequently. Then I discovered the reason why . . . Vitamin C was the culprit. Vitamin C is mostly Ascorbic Acid. I still take vitamin C , but have switched to the Ester C version. Since the switch, not one single canker sore . . . in many, many years.

  11. Many toothpastes contain an ingredient called Sodium Lauryl Sulfate (SLS). SLS is a strong detergent and has demonstrated in several studies to increase canker sore outbreaks and pain.
    I’ve only found a couple toothpaste types without SLS. Mainly the Walmart version on synsodine. It’s cut my canker soar problems by 90%.

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