Ever noticed a small whitish, yellow ulcer in your mouth that was slightly tingly in sensation and healed by itself? You most likely suffered from an aphthous ulcer or a canker sore. A one-off canker sore is usually not a concern for most people. But, when these canker sores are large, painful or take longer […]

Ever noticed a small whitish, yellow ulcer in your mouth that was slightly tingly in sensation and healed by itself? You most likely suffered from an aphthous ulcer or a canker sore. A one-off canker sore is usually not a concern for most people. But, when these canker sores are large, painful or take longer than usual to heal, they need your dentist’s attention. Canker sores are not the same as cold sores, do not occur on the lips, and are not infectious. So, what causes canker sores?

Identifying a Canker Sore

As mentioned earlier, canker sores are ulcers that occur inside the mouth. Most people who suffer from them do not know what they are or what causes canker sores. Canker sores are the most common type of oral lesions and affect around 20% of the world’s population. They are more likely to occur in women than in men and are also found to run in families.

They are usually small in size and are open ulcers that can make eating and other functions using your tongue painful. Before we understand what causes canker sores, it is important to know the types and how to identify them. Canker sores can be of three types:

  • Minor Canker Sores

    As the name goes, these are small in size(<1cm), appear in younger individuals between the age of 10-20 years and they appear and heal 3-4 times a year.

  • Major Canker Sores

    These sores are rare, usually over 2cm in size and mostly painful to the individual. Though they heal without scarring, these canker scores bring them to their dentist.

  • Herpetiform Canker Sores

    These are tiny sores that are rare and usually occur in older individuals. They occur in clusters, have irregular edges and heal within 1-2 weeks.

Expert opinion

  • Dr. Zita Antao Dental Director of Sabka dentist says "Canker sores are small, open ulcers that are commonly seen inside the mouth.”
  • Dr. Preethi Nagarajan Dental Director of Sabka dentist says "There are many reasons that cause canker stores.”
  • Dr. Reena Waghela Dental Director of Sabka dentist says "They are different from cold sores and are non-contagious.”
  • Dr. Ankita Gada Dental Director of Sabka dentist says "With the right treatment, your canker sores can be easily relieved.”

When Should You See Your Doctor?

Not all canker sores need you to seek dental treatment. When you learn more about what causes canker sores, you must avoid these causative or trigger factors. But, when do you see your doctor if you have canker sores?

As mentioned earlier, most of the canker sores heal by themselves without your dentist intervening. However, here are a few reasons it might be a good idea to visit your dentist if you have canker sore:-

  • Large, painful canker sores
  • Recurring canker sores or their frequent eruptions
  • Sores that last longer than 2 weeks
  • Extreme discomfort or pain while eating
  • Fever along with the eruption of canker sores

What Causes Canker Sores?

So, what causes canker sores? There are no causes that can be pointed out to be the exact causes of canker sores in the mouth. Studies show that they are caused due to a combination of factors and the causes are different for different people.

Here are some causes of canker sores –

  • Stress

    Chronic and frequent stress, including emotional stress, is one of the most common causes of canker sores in the mouth. Stress triggers off a certain chemical reaction in the body and results in canker sores. So people who ask “what causes canker sores in me frequently?” must evaluate their stress levels and try to reduce them!

  • Hormonal changes in women

    As we saw earlier, canker sores are more common in women. But, what causes canker sores in women more commonly than in men? Well, it is the hormonal changes that occur during menstruation. Many women see the appearance and disappearance of these canker sores during their monthly cycles.

  • Nutritional Deficiencies

    Many people prone to nutritional deficiencies like vitamin B12, folic acid, iron, zinc, etc., because their diet lacks these nutrients. But, these nutritional deficiencies cause canker sores.

  • Trauma/Injury

    Trauma-related canker sores are the most common ones that people suffer from. These canker sores occur due to sharp edges of teeth, trauma while using dental appliances, eating hard foods etc. The next time you get a canker sore after eating a hard food item, it might be your answer to “what causes canker sores?”

  • Drugs

    Many drugs can lead to canker sores. Some of these include aspirin, beta-blockers, immunosuppressants, NSAIDs, sulfa drugs, vasodilators, antibiotics, antihypertensives, among many others.

  • Helicobacter pylori infection

    Helicobacter pylori infections are notorious for causing peptic ulcers. But, they can also cause canker sores.

  • Toothpaste containing sodium lauryl sulphate

    Allergic reactions to toothpaste, mouthwashes etc., that contain components such as sodium lauryl sulphate can result in canker sores in some people.

  • Sensitivity to certain foods

    Eating some foods like citrus fruits, or other acidic fruits and vegetables can cause canker sores. However, among the many reasons for getting canker sores, these are not usually detected easily.

How To Get Rid of Canker Sores?

Now that we know what causes canker sores, here’s how you can get rid of them!

  • The pain is usually bearable. But, if it is too much or causes a lot of discomfort, some medicated topical application gels are useful
  • Using medicated mouthwashes prescribed by your dentist can provide symptomatic relief and also help your canker sores heal
  • Oral medications may sometimes be prescribed to treat canker sores. These can include steroids, Carafate or colchicine
  • If your canker sores are a result of nutritional deficiencies, then loading up on the essential deficient nutrients is a good idea

Canker sores are easy to treat and even more easy to prevent. If you are prone to them, you might still be troubled by them often but there are ways to reduce their chances of return:-

  • Eat healthy nutritious food
  • Keep your hormones balanced
  • Avoid biting into large pieces of hard foods that can hurt soft tissues in your mouth
  • Use a soft-bristled brush

If you are prone to canker stores and are often troubled by the question “what causes canker sores?”, visit our team of dental experts at Sabka Dentist!




Share & be a Hero!

I hope that this article has provided you useful insights about your oral hygiene and dental health. Share this knowledge with your friends and family and be the one to brighten their lives!


153 thoughts on “What are the Causes of Canker Sores?

  • Aayushi

    I get ulcers every month and I don’t know why. Now I know the reason. Thanks for the blog

    View all 2 replies
    • Pooja

      Do u have acidity prblm or any stomach issue get ur dental checkup regurlarly

      View all 2 replies
      • Aayushi

        Yes i do have stomach problem

        View all 1 replies
        • Esha Shah

          Very useful information.

      • Ramla shaikh

        Most canker sores go away on their own in a week or two, if you having pain that you could not able to control then go to a dentist, and this is very useful notes to know about canker sore very needfull article.

    • Joyline

      Good one!

  • Needa

    Nice useful information

  • Karishma

    Normally neglected ulcers can help diagnose underlying medical conditions in some cases.

  • Tasneem

    Usefull information

  • Jyoti

    This Blog is really helpful to me as i suffer with it many times!

  • Resh

    Any ulcer more than 2 weeks, please see a physician too

  • Manali Pandya

    Insightful. Thankyou for sharing it

  • A. Singh

    Very helpful blog

  • Shubhangi

    Mostly neglected topic ,thank u for information

  • Pooja


  • Mitali

    Your body irregularities can reflect in your oral cavity.keep a check

  • Priyankaghosalkar

    Everyone get ulcer at some point in our life maily due to our lifestyle. So the information very important and useful.

  • Sigi

    Worth reading!!

    View all 1 replies
    • Vivien

      Great Information

  • Dr.sonia

    Really nice blog

  • Tejal shah

    Useful information

  • Harshada

    Quite Informative

  • Priya

    Gud information

  • Binnu

    I used to wonder why I was having ulcer. Now this article makes it much clearer. Thank you for the information.

  • Shalony


    View all 1 replies
    • Janak thanth

      Great information ??

  • Megha Bansal

    Useful information.. It is worth reading

  • Shweta Desai

    Nice information

  • Dr Heena

    Great information

    View all 1 replies
    • Pawan Mishra

      Very general and ignored mouth issue we face. Article helped to have better understanding on it.

  • Esha

    Ulcers are very common and very ignored condition. If we take the above precautions we can avoid it

  • Anusha

    This blog is the most simplest way to understand mouth ulcers. Many patients use home remedies to treat them. But the main point of treatment is to find out the cause behind the disease and try to remove it, so that it does not reoccur. Since ulcers are very common people ignore them but next time you have ulcer try to find out the cause and treat them appropriately.

    View all 1 replies
    • Aayushi

      i thought ulcers are common they dont have any serious problem.

  • Madhura K

    Helpful information

    View all 1 replies
    • Tanushree


  • Dr.Aanal

    Good information

  • Dr. Saba

    Thankyou. Very informative blog indeed.

  • Zita

    Great read !

  • Kinjal

    I get ulcers very commonly and don’t know every time what to do but this information will be helpful now

    View all 1 replies
    • Aayushi

      You must visit dentist to have a checkup

  • Bhavana tripathi

    Ulcers are very common and this article help them to overcome from this.very informative article.

  • Farooq

    Very Useful information

  • Shaheda manjothi

    Nice article

  • Varsha

    ???very informative.

    View all 1 replies
    • Vipasha

      Nicely explained about ulcers,usually caused by internal reasons,which commonly people ignore yet suffer from it on day to day basis.This aritcle clears your query

  • Dr Swapna Randive


    View all 1 replies
    • Dr.Jaya

      By taking above precautions we can avoid ulcers.Useful .

  • Megha


  • Dr vini kanchan

    A very common finding, yet a very lifestyle-limiting pathology, in certain patients with recurring ulcers. Nicely explained and helpful tips.

  • Bhanu

    After reading this article, Just got to know that im under stress. Working on it.

  • Prerana

    Useful remedies to prevent ulcers..

  • Seema

    Very informative article.

  • Tanzila

    Useful information?

  • Dr Ankita Aggarwal

    Great article.

  • Pooja


  • Sneha

    Usefully infi

  • Dr aaksha

    Usually they are not painful , but if it stays for longer duration , then you should visit dentist

  • Aarti

    Good info

  • manan

    Very informative article

  • Mahajabin Raeen

    Very informative article

  • Suryakanta Jew

    Informative article..very nice

  • Sruti

    Informative article

  • sonal

    informative !

  • Janak thanth

    Great information ??

  • Pooja ponnana

    Good infomation

  • Mariya

    Great article

  • Farooq

    Worth Reading this Blog..

  • Esha Shah

    Very informative about cranker ulcers

  • Sonal

    Worth reading

  • Dipika

    Nice article

  • Vidhi

    Will definitely visit dentist soon. Thank you for the valuable information.

  • Minakshi tambe

    Nice information

  • Aishwarya

    Good content

  • Hemali Vora

    Most neglected topic in india, very informative article on this topic ?


    Nice article

  • Sigi

    Good content and Well explained

  • Sumedha


  • Megha

    Most of time, people neglect this..nice information



  • Nirali shah

    An article worth reading

  • Rukhsar

    Usefull information

  • Apurva


  • Bhavana tripathi

    Oral ulcers are very common problem .Very information article that describes types of oral ulcers and way to overcome from this.

  • pragati

    Informative article

  • Shaheda manjothi

    Very detailed explanation given … Very helpful

  • Esha

    Ulceration is very common due to stress which is common now a days. Cure the base and get the treatment soon

  • Ishani

    Very useful information

  • Seema

    Very common problem usually experienced by everyone, very nicely explained the causes and the treatment of them.

  • Apeksha vaghani

    Very common problem…very well explained about that

  • Saudah Gulati

    Any abnormality in the body reflects in the oral cavity!it should not be neglected!

  • Shwetketu

    Thank you for sharing this helpful information.

  • Pooja Shah

    This article explains abnormality that is neglected in our day to day life… which could be the cause of some major illness..

  • Very common problem n neglected as well..so much informative blog regarding canker sores..

  • Dr. Vishva patel

    Ppl avoid such symptoms n this article is informative enough . A must read !

  • Pooja ponnana

    Ulcers are most common among people and most of them avoid it by not knowing the correct reason .

  • Mariya

    Informative article

  • Divya shah

    Ulcer is common in all the ages.. This blog will help

  • Pooja pasnani

    In women especially due to hormonal changes such sores can occur and also due to lifestyle changes and stress

  • Shikha Sidhpura

    Amazing and helpfull blog ..!!??

  • Dr.Jaya

    Common issue faced by so many people so very useful article.

  • Sejal

    Nice article….very helpful in routine

  • Namrata Dharmadhikari

    Nice information ? worth reading

  • Shraddha

    A very troublesome and painful problem, informative article.

  • Kinjal engineer

    A very nice article giving complete details on canker sores. Worth a read

  • Shreya dharia

    Very helpful article

  • Very aptly written and explained

  • Bansi shah

    Very detailed information about something that is neglected by everyone.

  • Nidhi

    most common problem…easy to understand about ulcer to read this blog…nicely explained blog must read it

  • Drsachi

    Informative article about ulcers… worth reading..!!

  • Divya

    Well written

  • Mayuri

    Insightful. Good article

    View all 1 replies
    • Reshma Patel

      “Thank you so much for sharing all this great information.It is so appreciated!

  • Dr Kinjal Vyas

    Very well explained Article about canker sores. Healthy nutritious ,hormones balance,Avoid hard foods,Stress reduction procedure, use of soft bristle brushes are important things to prevent canker sores.
    On occurrence of it one should consult Dentist for it’s treatment .?

  • Ankita Aggarwal

    Effective and easy to follow solutions given

  • Akshi

    Quite clarified about ulcers nd the treatment now..

  • Rhythm shah

    Nicely explained !!

    View all 1 replies
  • Mahajabin

    Well explained..and briefly stated all the causes and the treatmnt options for those as well…thank you for the article ….

  • Vallari

    Nicely explained. It’s a very common problem. Will be very helpful

  • Rashmi

    Oral ulcers are very common problem infection.
    hormonal fluctuation.
    food allergy.
    menstrual cycle.
    vitamin or mineral deficiency.
    immune system problem.
    mouth injury.
    Effective and easy to follow solutions given

  • Good information was not answer of so many types to malocclusions thnk you sabka dentist.

  • Harshal Nikam

    I used to wonder why I was having ulcer. Now this article makes it much clearer. Thank you for the information.

  • Megha

    Really informative article and relatable many times

  • Akash

    Well explained. It’s a very common problem. Will be very helpful

  • Pandurang

    Good information was not answer of so many types to malocclusions thnk you sabka dentist.

  • Pooja Deshal

    Mouth ulcers aren’t contagious and usually go away within one to two weeks. However, if you get a canker sore that is large or extremely painful.or if it lasts for a long time without healing, you should seek the advice of a doctor

  • shabana

    This Blog is really helpful to me as with it many times!s

  • Nashra

    Canker sores are small open ulcer that are commonly seen inside the mouth. So this article will help us to understand on it.

  • Sunitha BS

    Good to know about mouth ulcers under oral health articles. Very informative article.

  • Nadeem

    Having tried just about everything to speed up the healing of mouth ulcers I believe I have found the best remedy for canker sores
    Well explained.Thank you sabka dentist.

  • Sanket Burte

    This article is very helpful to sloved canker sores problem.thanks for this information.

  • Dhwani Dave

    Many people don’t acknowledge it. Very helpful article

  • Susanna Puthenpurayil

    Informative topic

  • Pratiksha shukla

    Helpful blog..

  • Sonal Dhakane

    Nice information…

  • Priyanka Gulati

    Hence proves…every sore is not a CANCER sore but a CANKER SOre…

  • Nasir shaikh

    Very well explained

  • Shinal

    These sores are really common and this article will help to understand and treat it better

  • This blog has clearly explain of causes and cure about canker sores. Very well explained.

  • Rasika more

    Good topic ?

  • Pragati karekar


  • Sandhya

    Worth reading

  • Amrita Jha

    Ulcers are something we suffer from every now and then. This article lets you understand the reason behind it and how we can take care of it.

  • Monica Rani

    Canker sores or mouth ulcers are very common and there can be many reasons for it. Canker sores are little painful. This blog is very useful and it has very good information.

  • Shraddha

    Painful oral ulcers can create a lot of trouble to eat and drink the food. These ulcers can be formed due to smoking, eating acidic foods and many other reasons. I think this is a good blog for all who get this oral ulcers.

  • Shalvi

    This blog on canker sores is very much useful to know more about it. These painful oral ulcers can be of many types. This blog has good information on sores which I thought would not be there.

  • Rhythm shah

    I think acidic foods and hormonal imbalances are one of the most common reasons for these canker sores. Check out this blog. It has got a lot to say. Very good blog.

  • Megha

    A perfect up to the mark information on canker sores. It even tells you why they are so painful. Very good information

  • Rini

    Canker sore or you can say ulcers are very painful. I agree. This blog is written very nicely. They have given many options for remedies of these painful ulcer sores

  • Hatim

    i have seen your home remedy blog of canker sores also, it is very informative. Everyone should try these remedies at home if they are suffering from the same

  • Jena

    Good read…

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