Mouth ulcers 


Mouth ulcers are often uncomfortable but they usually clear up by themselves within a couple of weeks 

Mouth ulcers are painful round or oval sores that form in the mouth, most often on the inside of the cheeks or lips.

They're usually white, red, yellow or grey in colour and are inflamed (red and swollen) around the edge.

Although mouth ulcers can be uncomfortable, especially when you eat, drink or brush your teeth, they are usually harmless.

Most mouth ulcers will clear up by themselves within a week or two. You only need to see your GP or dentist if the ulcer gets worse or lasts for longer than three weeks, or if you develop ulcers regularly.

Read more about diagnosing mouth ulcers.

How common are mouth ulcers?

Mouth ulcers are very common, particularly in women and young adults. Most people will have one or two a year.

However, some people have mouth ulcers that come back regularly. Recurrent mouth ulcers are estimated to affect about one in every five people in the UK.

What causes mouth ulcers?

Most minor, single mouth ulcers are caused by damage to the mouth, for example by accidentally biting the inside of your cheek while eating, or from a sharp tooth, food or filling.

The cause of a recurrent mouth ulcer is not always clear, but it's likely to be a combination of factors including a genetic vulnerability and a certain trigger. Possible triggers may include feeling stressed or anxious, eating certain foods, hormonal changes and stopping smoking.

In some cases, recurrent mouth ulcers are a sign of an underlying health condition, such as iron deficiency anaemia or Crohn's disease.

Read more about the causes of mouth ulcers.

How to treat mouth ulcers

Most mouth ulcers heal within 10-14 days without causing any lasting problems, although severe ulcers may last for several weeks and could potentially leave a scar.

If you have a mouth ulcer that is particularly painful or is interfering with your daily activities (such as eating), some self-help measures and medications may help.

These can include using a soft toothbrush when brushing your teeth, avoiding hard and sharp foods, and using a mouthwash, spray, gel or lozenge to reduce the pain and help the ulcer heal faster. Read more about treating mouth ulcers.

Can mouth ulcers be prevented?

As the exact cause of most recurrent mouth ulcers is unknown, there is no certain way to prevent them. However, the following may help reduce your risk of developing mouth ulcers:

  • avoid damaging the inside of your mouth by using a soft toothbrush and avoiding hard, brittle or sharp-edged foods
  • avoid things you think may be triggering your ulcers, such as specific foods
  • learn some relaxation tips to relieve stress
  • make sure you maintain good oral hygiene, including brushing your teeth at least twice a day
  • have regular check-ups at your dentist – your dentist can spot and treat problems, such as sharp teeth or fillings, that could damage your mouth
  • eat a healthy, balanced diet rich in vitamins

Read more advice about dental health.

Page last reviewed: 06/03/2014

Next review due: 06/03/2016


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The 19 comments posted are personal views. Any information they give has not been checked and may not be accurate.

JiveJenny said on 22 October 2014

Miracle cure .I have suffered with continuous mouth ulcers since childhood. I have tried every over the county remedy for about 30 years and nothing ever worked. I would get a few minutes relief from bonjela and the extra strong bonjela paint which is now no longer available in the uk would help.
On going to the dermatologist at the hospital 7 years ago I was put on long term antibiotics - lymecycline. It took a few weeks for them to settle into my system and find the best way for them to work - I take one a day as soon as I wake up on an empty stomach with water. Now my ulcers have gone away almost. Instead of sufferering for 27 days out of 30 I am now ulcer free 27 days out of 30 and sometimes a whole month. If I do get an odd ulcer it goes away quickly.
Having spent most of my life in pain - speaking eating and drinking, and suffering with awful tonsilitus 2 or 3 times a year when the ulcers went to my tonsils I am now pain free and tonsilitus free. I only wish I had been told about this treatment many years ago.

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Buddys mum said on 06 September 2014

Also never use bonjella, my dentist told me that only irritates them more.

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Buddys mum said on 06 September 2014

I have 2 of these painful little ratbags. One is on my tongue and it is a monster, the other is in a stupid place that I can't reach. I want to eat but they won't let me. I want them gone both of them by tuesday because I'm going on holiday. Last thing I want on holiday is to be dealing with ulcers. I'm using iglu.

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emmawhittonbrett said on 14 August 2014

I used to have awful recurrent ulcers, but since stopping using toothpaste with Sls (sodium lauryl sulfate) I rarely get any. Aldi dentitex toothpaste is Sls free :) it's worth shopping for a more expensive version if you don't have an Aldi though!

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emilywhite92 said on 19 May 2014

hi i have suffered wit recurrent mouth ulcers ever since i was little, im now 21, but when i get them i gets lots of them and very big ones like every month, ive tried many different treatments such as creams liquids, mouthwash and changing toothpastes, but everything seems to make them bigger and more painful even sometimes i just get more, i spoke to a doctor over the phone and they just said keep using the treatments i am, even though i said they don't work, i currently have several at the moment, which are very painful to the point of hurting to eat and swallow saliva, if anyone could offer any advice that would be brilliant, thank you, Emily

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Pipsqueaksmum said on 15 April 2014

My mouth/lip is extremely swollen and painful after biting the inside of my mouth by accident. The problem is, I can't stop touching it with my finger and tongue! I'm currently using an ice pack and have taken Ibuprofen. Just this minute I discovered a painful swollen gland a immediately below my jaw line. Do you think they could be directed!

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Jmarie80 said on 10 February 2014

To jmay72 below......... PLEASE seek a second opinion urgently if you still have these ulcers, it could be something quite serious. Demand tests. .... please update here.
I use Zinc supplemets daily and I now never get an actual mouth ulcer, it really does work. I used to get them all the time. I do sometimes hurt my gums if I brush too vigorously and this can get infected and be as bad as an ulcer. There used to be a really good paste you could get over-the-counter for ulcers but they stopped doing it and now no treatment works.

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Linusj67 said on 04 September 2013

I am 45 and have suffered from mouth ulcers my entire life. Some years ago I had an issue with some of my joints swelling. Ortho Dr thought I had torn some cartilage playing sports and even performed surgery on one knee. It turned out to be an autoimmune problem and I was referred to a Rheumatologist. After running some blood tests (sedimentation level, etc) the first question the Rheumatologist asked me was, "Do you ever get mouth ulcers?" I couldn't believe he asked that question! He told me that mouth ulcers are commonly a symptom of an auto-immune disorder. He said it is an overactive inflammatory response to injury, illness, stress, etc. He gave me a prescription for Prednisone in reducing dosages. By day 2 my mouth ulcers were gone. Ulcers were not even the problem for which I sought help. Prednisone carries with it its own set of issues so it is not to be taken lightly but when I have a severe problem I know it will eliminate the ulcers.

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chelle88 said on 14 July 2013

Right, I have had ulcers all my life from when I was a baby pretty much. I have had them really horribly bad, and mild, and everything in between. The other day, Wednesday to be exact, I collapsed in the heat and had a seizure. During the seizure I must have bitten hard down onto my tongue and cheek and surrounding areas, because they said my jaw muscles seize up during a fit. The thing is, I knew that this would turn into an ulcer. The side of my tongue was sore and my cheek too. But today, Saturday, the pain and the ulcerations have come out in full show, and I'm in absolute agonising pain, Its absolutely horrific. And I have dealt with bad ulcers, but this is horrendous. I cant even swallow my own saliva, talk, drink water, let alone eat! I went to the walk in clinic today, I have been given Difflam mouthwash, which hurts without diluting it, and 30mg codeine tablets. I have also got strong tramadol tablets, anbesol, bonjela. All of these things only numb the pain very briefly. Its ridiculous. So does anyone have any other recommendations? Salt water has been mentioned but if I'm honest I'm really scared about that! The pain is intense, hurts all in my jaw and neck and ear. I have tried putting germolene antiseptic ointment on the outside of my cheek to try and numb it that way. I will be so grateful for any suggestions or help or anything!

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neuraljam said on 17 June 2013

I've suffered from mouthfuls of ulcers for a number of years, and it seems that I have two major triggers: tomatoes and SLS (as mentioned by others).

It took me some time to find a toothpaste without SLS, so in order to hopefully save some people some legwork, here's a tip: Boots Expert Dental Toothpaste. It even explicitly says on the pack that it does not contain SLS (though it didn't at the time when I was first looking for it!)

I hope this helps someone :-)

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hgower said on 17 March 2013

I always get them as soon as I feel it I starting rub some vegemite on it, marmite might be useful too, it stings but doing it a few times a day cures it quicker, I wish I could end it but it is so hard as I get it frequently, mainly when I don't have rest at night, and I don't eat much vegies and fruits either, my mums theory is my body is not cool from within, so it could give these mouth ulcers she says that you need the inside of your body to be cool y drinking king coconut water, eating barley or sago to hels cool your system down, you can get recipes for this on the internet, there may be some truth to it by the way my b12 is high 725, it should not be above 7oo according to australian standard results could this be the reason, on the internet it states maximum is 66o, why is it high all the others were normal except for esonohils was 1.8 slightly low, doctor said I could have had an infection when the test was done, everything else normal limits, I like drinking milk and wondered if this was the cause of my b12 been high the doctor was not concerned. Did three tests and they were all the same esonohils were ok in the others

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wilycat said on 26 February 2013

I am 31 and have had bouts of multiple mouth ulcers. I have always noticed that I have been mentally or physically run down and found they are ther'ye at thier worst when feeling down or stressed. I found a product you can get from over the counter is very effective.

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Elphie81 said on 12 February 2013

I have suffered with ulcers for as long as I can remember. At 31 yrs old I now know that the following cause them- sweets ( esp hard boiled) sweet drinks, alcohol, being run down. I currently have ten ulcers, but am full of a cold and pretty run down. It's rubbish!

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smileee said on 18 June 2012

Hi. Having suffered from reoccuring mouth ulcers for the last 3 years, ie never having a mouth free of an ulcer for that amount of time, and at times having 5 or 6 ulcers at time, I am now free of them finally! This was due to changing my toothpaste to a brand that does not contain SLS (sodium lauryl sulfate). I was surprised to see that the section about reoccurring ulcers does not mention toothpaste containing SLS as a possible cause, amongst all the different types of foods that could cause mouth ulcers. I cannot believe that after 3 years a simple change to an SLS free toothpaste has done the trick. I have now been free of ulcers for 6 weeks and every morning I wake up I still can't believe I
am now free of that misery! I know that this may not be the case for everyone but I urge those who have not made that change to do so and see what happens. I spent a fortune on vitamins (especially B12, Iron and Vit A), I had numerous blood tests done and all came back normal and not lacking in any vitamin and saw a consultant so I was at a total loss - give it a go.

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piggywiggy said on 30 December 2011

SLS free toothpastes are fabulous, as are SLS free soaps and shampoos! We've been using them for at least 8 years - still hasn't stopped me getting huge, recurrent mouth ulcers though! However if it works for some people, then that's fantastic and I'd certainly recommend giving an SLS free life a go anyway.

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healthie said on 16 October 2011

I agree with mg92aa. I lived 54 years free of this problem, then for the past four years have suffered recurrent oral ulcers which give pain that sometimes lays me low for days on end. Successive doctors display ignorance, disinterest and a lack of even the willingness to ask the right questions, or to find the time to consider this condition further. This is unscientific. There HAS to be a cause or set of causes, some trigger. I have changed doctor surgeries on account of a poor quality perceived of help, only to find new doctors that don’t progress the inquiry. My dentist has helped a little (e.g. by suggesting diphlam mouthwash). I live an otherwise healthy lifestyle – organic food, a high dietary proportion of fresh vegetables etc., have exercised in various ways, am aware of natural health practices. By the natural health principles I espouse, to not root out a problem is alarming. I would be glad if any further anecdotal solutions (like that of seasideboy) were to be posted… I’ve heard (from a chemist) about SLS too.

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seasideboy said on 05 August 2011

Quite by chance around 25 years ago, I found that Chewing Gum was the cause of my extremely regular mouth ulcers. Since that chance discovery, I have never used chewing gum again, and I have been just about free of mouth ulcers ever since. For me that was a simple cure, no idea why of course, but its worked for me. I implore all mouth ulcer sufferers to try it. By the way I often mention this transformation to the various GPs I have; but I get the feeling they are not really interested in my comment. That's no skin off my nose, as it works for me, but don't you just wish more GPs would listen to their patients, and pass on that information to their patients. After all staying off chewing gum is a totally safe no-risk process and must be worth a try to sufferers of this wretched irritation.

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anidea said on 19 November 2009

I read on another page that a chemical in toothpaste - sodium lauryl sulfate - that makes it froth up can cause ulcers. You can buy ones without SLS in health shops i think. Hope this helps.

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mg92aa said on 28 June 2009

This cannot possibly be the state of the art in the defeat of mouth ulcers! Pleas - we all know to use Bongela, but we want to prevent ulcers. You should be posting diet and lifestyle information, detailed information, allowing us to prevent rather than treat

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