Mouth Ulcers: Causes, Symptoms, Treatment & Prevention (2026 Complete Evidence-Based Guide):
An ulcer occurs in the body when an area of tissue fails to heal properly. One type of ulcer occurs in the mouth: a small sore that can be very painful and usually develops on the brush. Mouth ulcers are rarely contagious and typically heal themselves within two weeks; however, they do not normally cause any lasting damage to your oral cavity.
The most common reasons for developing a mouth ulcer include trauma, oral hygiene problems, stress, B vitamin deficiency, hormonal changes, and secondary effects of medication or underlying medical conditions. If you have persistent mouth ulcers that last longer than three weeks, please see your doctor for further evaluation.
Medically Reviewed by Dr. Humaira Latif, MBBS
Gynecologist & Obstetrician | Ultrasound Specialist | Women's Health Educator
Last Updated: June 2026.
Table of Contents:
Visit our website for the latest info about mouth ulcers:
- Definitions,
- Types of Mouth Ulcers,
- Symptoms Of Mouth Ulcers
- Causes,
- Risk Factors,
- Diagnosis,
- Treatments,
- Home Remedies,
- Prevention,
- Ulcers in Children,
- Ulcers During Pregnancy, and
- Key takeaways from our comprehensive guide.
- Frequently Asked Questions.
- Conclusion.
- Related Articles
- References.
- Author
- Medical Disclaimer
- Free Oral Hygiene Guide Pdf Downloadable Link.
1. What are Mouth Ulcers?
Mouth ulcers are flat sores that form on the surface of your oral tissue. Often referred to as canker sores or recurrent aphthous ulcers, they are shallow breaches of the oral lining that can occur inside your lips, inner cheek, floor of mouth, on your tongue, soft palate, or on your gums. Unlike cold sores, which are caused by the herpes virus and occur on or around the mouth; mouth ulcers develop within the mouth.
While mouth ulcers are not dangerous and generally heal on their own, they may cause pain or discomfort when performing normal activities (eating, drinking, brushing teeth, speaking) until they have healed.
Mouth ulcers are usually harmless and will typically heal on their own; however, if you experience recurrent or abnormal-sized ulcers, you may need medical assistance as they could be indicative of an underlying medical condition.
2. Types of Mouth Ulcers.
1.Minor Aphthous Ulcers:
These make up roughly 80% of all instances; they're small & round or oval-shaped, have a yellowish-white center and red outer ring - most will resolve on their own without treatment.
2.Major Aphthous Ulcers:
These have a much deeper and larger size than minor ulcers, are associated with much more pain than minor ulcers, take longer to heal and may result in a scar.
3. Herpetiform Ulcers:
These ulcers are often confused with herpes virus ulcers, but are not viral in nature. Herpetiform ulcers appear in clusters of tiny (nickel-sized) ulcers which can come together as an extensive large painful area.
Mouth Ulcer vs Cold Sore
Cold sores and mouth ulcers are not the same condition even though they get mistaken for one another frequently.
3. Symptoms of Mouth Ulcers:
There will be different symptoms based on the size and how bad the ulcer is.
Symptoms often include:
- Sore (circular or elliptical)
- Centre of the sore is white, yellow, or grey
- Around the outside of the sore is bright red
- Sore will burn and you will tingle before you have the sore
- Can't eat spicy or sour foods because it causes pain
- Can't chew comfortably
- Will have pain while brushing your teeth
- When you speak you may have a small amount of discomfort.
If you have a larger ulcer you may also have:
- Can't swallow
- Lymph nodes may be swollen
- Fever (rare)
- Very painful and makes it difficult to eat.
Stages Of Healing:
4. The Development of Mouth Ulcers(Causes).
Mouth ulcers are caused by a variety of factors, and in many cases, there is no single identifiable cause. Rather, multiple factors typically act to irritate the fragile tissue of the mouth and stimulate inflammation (inflammation can be defined as the process by which the body's immune system pushes forth an increase of blood to an area, causing redness and swelling).
Knowing the underlying cause is necessary for treatment since treatment strategies seek to address the underlying source of inflammation instead of providing symptomatic relief from the pain associated with mouth ulcers. Some of the most frequent causes of mouth ulcers include:
1. Trauma.
Minor injuries to the oral lining are the most common cause of mouth ulcers. A mouth ulcer can develop even as a result of a minor trauma; two examples of this might include when you accidentally bite yourself inside your cheek or when you brush your teeth too forcefully.
Poor fitting dentures, fragmented or jagged teeth or orthodontic braces causing friction are all ways that trauma may cause a mouth ulcer. Traumatic mouth ulcers usually heal within 14 days (or less) after the source of irritation (i.e., whatever caused the mouth ulcer) has been eliminated.
2. Psychological Stress.
Psychological stress is known to trigger recurrent aphthous ulcers.
3. Stress
Stressful periods of time at work, taking exams, being anxious about something, being sleep deprived and/or experiencing emotional turmoil can temporarily change your body’s immune response, therefore making it much more likely that you will develop mouth ulcers.
While stress does not directly cause mouth ulcers, it contributes significantly to increases in the number of mouth ulcers suffered by people who are already susceptible to them.
4. Hormonal Influences
Hormonal changes and fluctuations can negatively affect women's health and therefore may negatively impact their ability to maintain good oral hygiene. Women who are susceptible to developing mouth ulcers often experience the development of mouth ulcers during the time of their menstrual cycles; however, hormonal changes and fluctuations may also affect men's health.
5. Food Sensitivities.
Some foods can irritate your mouth by irritating the lining of the mouth or triggering recurrent ulcers, especially in those who have sensitivities. Common food triggers include:
- Pineapple
- Citrus fruits
- Nuts
- Chocolate
- Coffee
- Salty snacks
- Spicy foods
- Acidic beverages
- Tomato-based products
Keeping a food diary can help identify what triggers recurrent mouth ulcers for you.
6. Nutritional Deficiencies:
Some recurrent mouth ulcers can be caused by vitamin or mineral deficiencies. Deficiencies of vitamins and/or minerals that are commonly associated with onset of recurrent mouth ulcers include:
- Vitamin B12
- Folate (Vitamin B9)[
- Zinc
- Vitamin B6
- Iron
7. Certain Medications
Some medications can cause an increase in the risk of developing recurrent mouth ulcers. Some examples of medications that can increase the risk of recurrent mouth ulcers are:
8. Non-steroidal anti-inflammatory drugs (NSAIDs):
- Nicorandil
- Certain beta-blockers
- Some chemotherapy agents
- Bisphosphonates
- Methotrexate
- Immunosuppressive medications
Never stop taking a prescribed medication without consulting with your healthcare provider.
9. Smoking Cessation:
It is interesting to note, some people will develop temporary recurrent mouth ulcers after quitting smoking. Researchers believe this is due to the oral lining thickening as a result of tobacco. Quitting smoking returns the oral lining's thickness to normal, therefore, for a short time, recurrent mouth ulcers may be more visible.
Quitting smoking :
has significant health benefits and should always be encouraged.
A variety of underlying medical conditions can be associated with the repeated or chronic occurrence of mouth ulcers; some examples include:
- Celiac disease,
- Inflammatory bowel disease (such as Crohn’s and ulcerative colitis)
- Behçet’s disease
- HIV infection
- Autoimmune disorders
- Cyclic neutropenia
- Immunodeficiency disorders
- In situations where there are frequent and/or severe mouth ulcers, or if there are additional symptoms present, it is important to seek further medical evaluation.
5. Factors That Increase Your Chances of Developing Mouth Ulcers:
There are many reasons why someone may develop a mouth ulcer, but certain factors increase your risk of having one develop.
Non-modifiable risk factors are:
- History of family members with mouth ulcers
- Being of female gender
- Being under 40 years of age
- Being genetically predisposed
- Modifiable risk factors include:
- Poor oral hygiene
- Stress
- Poor diet
- Quitting smoking
- Certain foods can trigger the development of mouth ulcers
- Trauma to the oral/eating area
- Poor-fitting dentures
- Not getting enough sleep.
6. Diagnosis.
What Types of Testing Are Used to Diagnose Mouth Ulcers?
A medical history and physical exam will usually provide the information needed for a healthcare provider to make a diagnosis of mouth ulcers.
The provider may ask about:
- When did the ulcer first appear?
- Is this your first ulcer or do you have a history of recurrence?
- How much pain are you experiencing?
- Have you been through any most recent stress or trauma?
- Are you taking any medications?
- Do you have other conditions that affect your digestion?
- Have you been experiencing any recent weight loss, fever, or skin rashes?
Once the history of the ulcer is established, the healthcare provider will conduct a thorough examination of the mouth and note the size and location of the ulcer(s) and if there are any ulcers that look similar.
Laboratory Tests:
If the ulcer(s) are recalcitrant, recurrent, or associated with another symptom, the healthcare provider may recommend additional examinations, such as:
- CBC
- Iron studies
- Serum ferritin
- Vitamin B12 level
- Folate level
- Zinc level
- Glucose testing (especially if you suspect a diabetic condition)
- Celiac screening
- HIV testing (based on the clinical picture)
Serological screening for autoimmune disorders, if this is the presenting symptom.
Also, consider referring patients with an ulcer that has been present for over 3 weeks to a specialist in oral medicine or obtaining a biopsy if the patient is a heavy smoker or drinker to rule out oral cancer.
Indicators of a Possible Health Problem:
See a doctor immediately for an evaluation if any of these apply to you:
- An oral ulcer that’s been present for over 3 weeks
- An oral ulcer that’s enlarging quickly
- An oral ulcer that reoccurs every few weeks
- Difficulty swallowing food or liquids
- A fever that is higher than normal
- A loss of weight you cannot account for
- Any swelling or enlarged lymph nodes in your neck
- Any oral ulcer that has persisted in anyone who uses tobacco or alcohol
- An oral ulcer with eye inflammation, genital ulceration, or skin lesions
- Severe pain that prevents you from being able to eat or drink.
The sooner these symptoms are assessed, the quicker serious conditions may be identified and treated appropriately.
7.Treatment:
The treatment of mouth ulcers varies depending on the cause, severity, frequency and duration of the ulcers. Most minor ulcers will heal by themselves within 7-14 days.
Treatment goals are to relieve pain, promote healing, prevent a secondary bacterial infection and, if applicable, identify and treat an underlying medical condition.
Currently, there is no known cure for recurrent aphthous ulcers; however, various treatments supported by scientific evidence exist that can help reduce the level of discomfort experienced from an ulcer as well as improve the rate of healing. The main goals objectives involved with mouth ulcer treatment include:
To reduce discomfort or pain (burning) associated with the ulcer.
The treatment of mouth ulcers varies depending on the cause, severity, frequency and duration of the ulcers. Most minor ulcers will heal by themselves within 7-14 days. Treatment goals are to relieve pain, promote healing, prevent a secondary bacterial infection and, if applicable, identify and treat an underlying medical condition.
Currently, there is no known cure for recurrent aphthous ulcers; however, various treatments supported by scientific evidence exist that can help reduce the level of discomfort experienced from an ulcer as well as improve the rate of healing. The main goals objectives involved with mouth ulcer treatment include:
- To reduce discomfort or pain (burning) associated with the ulcer.
- To assist in accelerating the healing process of the ulcer.
- To provide anti-inflammatory effects,
- To assist in preventing the development of a secondary bacterial infection.
- To allow the patient to eat/drink comfortably.
- To determine and eliminate any underlying cause of the develop ulcer.
- To reduce the frequency of recurrence of the ulcer.
1) Topical Medications.
For most uncomplicated mouth ulcers, topical medications are the first line of treatment.
Antiseptic Mouthwashes
Antiseptic (aka antimicrobial) mouthwashes help to reduce the number of bacteria in the mouth; therefore reduce the risk of developing a secondary bacterial infection.
Using an antiseptic mouthwash may:
Keep mouth ulcers clean.
Reduce the irritation caused by eating.
Assist in the healing process.
Decrease the level of discomfort while eating.
Topical Corticosteroid Preparations
Topical corticosteroid preparations are frequently used to treat recurrent or painful aphthous ulcers; topical corticosteroids have an anti-inflammatory effect. Use of topical corticosteroids for the treatment of mouth ulcers may produce the following benefits: less pain; reduced redness; shorter length of time to heal and there is less likelihood that the ulcer will develop into a large ulcer.
Topical corticosteroids will be more effective if used as soon as they begin to feel the "tingling" sensation associated with an impending mouth ulcer, rather than waiting until the ulcer has completely developed
Oral Gels & Barrier Pastes:
Barrier products have been developed to cover the ulcer and provide protection.
Some of the benefits of barrier products include:
- Less irritation when eating
- Decreased pain
- Increased comfort when talking
- Increased ease of eating and drinking
Local Anaesthetic Gels:
These gels numb the ulcer temporarily. Local anaesthetics are helpful for:
- Before meals
- Before you brush your teeth
- Before talking for long periods of time
The effect will usually only last for a short time.
2. Pain Relief Medications,:
Your health care provider may prescribe you pain relief medications for severe discomfort when indicated. It is important to always follow your doctor's orders regarding medications for children, seniors, pregnant and breastfeeding mothers, people with liver disease or kidney disease.
3. Nutritional Supplements:
If you receive blood work with positive confirmation of vitamin/mineral deficiencies, your doctor may recommend taking the following supplements:
- Iron
- Vitamin B12
- Folate
- Zinc
- Vitamin B6
Improving your body's nutritional deficiencies will decrease the incidence of mouth ulcers over time.
4. Treat the Cause of the Ulcer:
Mouth ulcers that are persistent may only respond to treatment once the disease responsible for creating the ulcer has been identified and controlled. Some of the medical conditions that may cause persistent mouth ulcers include:
- Celiac disease
- Inflammatory bowel disease
- Behçet disease
- Autoimmune disease
- HIV
- Blood disorders
If you treat the ulcer and not the underlying cause, you will likely have another episode.
5. Laser Treatment:
Laser therapy with low-level lasers has recently started to attract more attention as a possible treatment for recurring aphthous ulcers. Some possible benefits of laser therapy are:
8. Home Remedies for Mouth Ulcers:
There are many home-care remedies for mouth ulcers that are effective for relieving the discomfort of mouth ulcers and assisting in the healing process. The best results come when you follow these tips along with practicing good oral hygiene as well as eating a healthy diet.
1. Rinse with Warm Salt Water:
Rinsing your mouth with warm salt water may help to:
• Reduce swelling
• Clean the ulcer area
• Promote healing
Use a mild salt water solution to avoid causing more irritation.
2. Rinse with Baking Soda
Research shows that rinsing with baking soda can neutralize the acids in the mouth and decrease irritation for some people.
3. Drink Plenty of Fluids:
Keeping your throat and mouth moist with fluids (i.e., drinking enough water) will help to keep your mouth moist to stimulate the body's natural healing processes.
4. Eat Soft Foods
When you have mouth ulcers, choose foods that are soft and easy to eat. For example:
• Yogurt
• Oatmeal
• Rice
• Mashed Potatoes
• Bananas
• Soups
Foods that cause increased pain should be avoided.
5. Avoid Certain Irritating Foods
Avoid the following irritating foods temporarily:
• Spicy Foods
• Citrus Fruits (i.e., oranges)
• Foods made with vinegar
• Salty Snacks
• Hot Drinks
• Mouthwashes that contain alcohol
6. Use a Soft Toothbrush:
Using a toothbrush with soft bristles will help to minimize the amount damage caused by brushing to the area around the ulcer.
7. Manage Your Stress:
Managing stress may help you reduce the number of times you get mouth ulcers. Good stress management tips include:
• Regular exercise
• Meditation
• Deep breathing exercises
• Getting adequate rest at night
• Relaxation exercises
8. Maintain Good Oral Hygiene:
Be gentle when you brush your teeth two times each day and perform regular cleanings between your teeth to keep the amount of bacteria that may accumulate between your teeth to a minimum.
9. Tips to Avoid Mouth Ulcers:
Mouth ulcers cannot all be effectively managed, but living a healthy and balanced lifestyle can definitely help minimize your chances of getting them and can help alleviate your symptoms.
Everyday Prevention Tips:
- Use a soft toothbrush and brush gently.
- Floss daily to keep your mouth clean and healthy.
- Do not chew on your cheeks or lips.
- Get your broken or improperly fitting dental work repaired as soon as possible.
- Eat a well-balanced diet with lots of vitamins and minerals.
- Drink plenty of water throughout the day.
- Identify and avoid food triggers.
- Manage your stress by using techniques such as relaxation.
- Ensure that you get enough sleep every night.
- Go to the dentist regularly for routine care.
Foods that promote Oral Health
Incorporate foods that are high in the following nutrients:
- Iron
- B12
- Folate
- Zinc
- Protein
- Fruits and vegetables
- Whole grain foods
- Dairy products (if appropriate)
10. Mouth Ulcers in Children:
Mouth ulcers frequently occur in children because of the following:
- Minor trauma
- Viral infection
- Nutrient deficiency
- Braces
- Stress
- Poor oral health
Encourage the following practices:
- Adequate hydration
- A diet of soft, nutritious foods
- Gentle brushing
- Avoid spicy or acidic food
A healthcare provider should evaluate children with mouth ulcers if they:
- Last longer than two weeks
- Are associated with a high fever
- Are interfering with the ability to eat and drink
- Are a recurring problem
- Have caused dehydration.
11. Oral Ulcerations During Pregnancy:
Significant fluctuations in hormones and levels of immunity that are present during pregnancy can lead some pregnant women to experience mouth ulcerations.
Contributing Factors:
- Changes in hormones
- Increased nutritional needs
- Insufficient Iron
- Insufficient Folate
- Insufficient Vitamin B12
- Morning sickness impacting nutrition
- Stress/Fatigue
The majority of oral ulcers during the pregnancy will not be significant issues and will heal with supportive treatment.
Pregnant women should seek physician care for oral ulcers if they:
- Are persistent
- Are recurrent
- Are significantly painful
- Have fever associated with the lesions
- Exhibit nutritional deficiencies or anemia
A nutritious diet, proper administration of prescribed prenatal vitamins, adequate hydration, and creating and following good oral hygiene will assist in reducing the risk for oral ulcerations during pregnancy.
12. Key Points:
Most oral ulcerations will resolve spontaneously within 7-14 days.
The mainstay of treatment will be to reduce pain and maintain good oral hygiene.
Recurrent oral ulceration may indicate a vitamin deficiency or underlying medical condition.
Avoiding triggers for oral ulceration, eating properly, and managing stress will help to reduce the incidence of recurrent oral ulcerations.
Seek medical attention for oral ulcerations if they last longer than 3 weeks, recurrent, painful oral ulcerations, or associated with other concerning medical findings.
13: Frequently Asked Questions:
1. What causes mouth ulcers?
Dental injuries, emotional imbalance and stress, hormonal changes, vitamin and mineral deficiencies (iron, folate, zinc, vitamin B12) medications, food sensitivities, immune system issues (celiac disease or inflammatory bowel disease) could lead to mouth ulcers. There may not be one or multiple reasons for the occurrence of these ulcers.
2. How long do mouth sores last?
Most small sores usually heal themselves from 7 to 14 days without scarring, larger or deeper sores will take between 2-6 weeks to heal. If the sore doesn't heal by 3 weeks, you should see your doctor.
3. Is it possible to spread mouth sores?
Non-contagious mouth sores (canker sores, aphthous) are not spread through kissing, eating from the same dish/utensil, or through close contact with someone who has them. However, cold sores, caused from the herpes simplex virus, are contagious and completely different problems.
4. What is the quickest way to heal a mouth sore?
There isn't a way to instantly cure an ulcer but if you maintain good oral hygiene through good brushing/flossing habits, low-acid and spicy food intake, the use of protective gels and prescribed topical applications, correct vitamin and mineral deficiencies, proper hydration and time, your ulcers will heal in 1-2 weeks.
5. What vitamin deficiency leads to frequent mouth ulcers?
Deficiencies in iron, Vitamin B12, folate (Vitamin B9), zinc and, sometimes, Vitamin B6, can all be linked with the development of frequent mouth ulcers or can aggravate the frequency of development. If you experience regularly developing mouth ulcers, it is suggested that you see your physician for a blood test to evaluate your nutritional status.
6. When should I go to the doctor for a mouth ulcer?
If any of the following occur, you should consult your physician regarding your mouth ulcer:
Lasts longer than three weeks
Is larger than average or significantly more painful than usual
Recurs frequently
Makes it difficult to eat or drink
Accompanied by fever, weight loss, swollen lymph nodes or other unexplained symptoms
Persistent mouth ulcers should be evaluated to eliminate any underlying cause.
7. Can stress contribute to the growth of mouth ulcers?
Yes. Some people will find that high levels of emotional stress or insufficient sleep will either cause the emergence of or amplify the development of recurrent mouth ulcers. Engaging in activities that relieve stress, including regular physical activity, adequate rest, relaxation techniques, and a balanced lifestyle may help to decrease the number of recurring ulcers.
14. Conclusion:
and/or significantly interferes with a person's ability to eat, drink, or talk should be evaluated by a healthcare provider. This is especially true if there is any sign of abnormal tissue or lesions on or around the mouth.
Ongoing research into the mechanisms causing mouth ulcers is likely to lead to new ways of managing this common problem. Additional studies will also contribute to developing improved treatments for different types of mouth ulcers. If you experience recurrent mouth ulcers, please talk with your healthcare provider about ways you may reduce their occurrence and how to manage them effectively when they do happen. Thank you for taking the time to read this article on mouth ulcers!
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16.References:
1. National Health Service (NHS), UK
Topic: Mouth Ulcers
Last Reviewed: 11 March 2024
2. MedlinePlus – U.S. National Library of Medicine.
Topic: Mouth Ulcers (Medical Encyclopedia)
Review Date: 1 January 2025
3. Cleveland Clinic:
Topic: Canker Sores: Symptoms, Causes & Treatment
Last Updated: 18 September 2025
4. Cleveland Clinic:
Topic: Mouth Ulcers: Types, Causes & Treatment
Last Updated: 6 June 2023
5. Mayo Clinic
Topic: Canker Sore – Symptoms and Causes
Published/Updated: 3 April 2018
6. National Center for Biotechnology Information (NCBI) Bookshelf – StatPearls
Topic: Aphthous Stomatitis
Latest Update: 2022 (StatPearls Publishing; regularly updated)
7. PubMed – National Library of Medicine:
Topic: Treatment of Recurrent Aphthous Stomatitis: A Systematic Review (Med Oral Patol Oral Cir Buccal)
Published: January 2023
8. American Academy of Family Physicians (AAFP):
Topic: Canker Sores
Updated: October 2023
17. About the Author:
Dr. Humaira Latif, MBBS
Gynecologist & Obstetrician | Ultrasound Specialist | Medical & Health Content Creator
Dr. Humaira Latif is an MBBS-qualified physician with over 14 years of clinical experience in Obstetrics and Gynecology. She is dedicated to creating evidence-based, easy-to-understand health content to help readers make informed healthcare decisions.
18. Legal Disclaimer:
This article contains information on medical matters, but does not take the place of actual medical care from your local healthcare provider. If you have had sores in your mouth for a long time or have other serious medical problems, please contact your local healthcare provider immediately.
Reviewed June 2026.
19. Free Oral Hygiene Guide Pdf Downloadable Link
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