06-04-2025
Understanding the source of a mouth ulcer can uncover how best to treat it. Mouth ulcers can appear if you need to improve your oral hygiene, but also if there are needs to improve your whole body health and mental wellbeing. In this article, we will answer the question of ‘what is a mouth ulcer?’, and discuss the most common causes of ulcers, types of ulcers, and treatments for the condition.
Key Takeaways
- Keeping your mouth clean and using high-quality products will be essential to preventing getting mouth ulcers and reducing the risk of damage to your mouth and keeping it as healthy as possible.
- There are varying types of mouth ulcers. If you get them frequently, you may have Recurrent Aphthous Stomatitis (RAS) in which case you should consider improving your diet and seeing a doctor
- Although they look similar, cold sores and mouth ulcers are different: mouth ulcers are not contagious and the source of them is unclear
- Mouth ulcer treatment is dependent on its severity. Typically, they will heal over a week or two and all you need is to keep your oral hygiene optimal. However, if it persists and is still painful, go to your doctor for a consultation or prescribed treatment.
What are mouth ulcers?
Mouth ulcers are painful and uncomfortable sores that occur inside the mouth. Most mouth ulcers will be red or yellow spherical sores on the gums, tongue, palate, inner cheek, or inner lip.
Despite the fact they can be painful, and occur in uncomfortable clusters, an ulcer in the mouth is a common, non-serious condition that will tend to disappear on its own and not require medical treatment. Though similar sores around the body may be a sign of one, mouth ulcers are not an STI (sexually transmitted infection).
Mouth Ulcer Causes
Mouth ulcers have several common causes, meaning often what causes mouth ulcers is unclear. A large proportion of ulcers in the mouth are caused by damage (trauma) to the oral mucosa lining, for example:
Gum damage from teeth cleaning
Hard/sharp foods
Accidentally biting the tongue or cheek
Poorly made tooth fillings
Poorly fitted dentures
Hot food/drink burns
Though it is frequently cited as the most common mouth ulcer cause, oral damage is not the only reason why a mouth ulcer may occur. Stress and anxiety, the process of stopping smoking, hormonal changes (mainly due to periods), and food allergies can all be factors behind the development of mouth ulcers. As well as this, children/adolescents, people assigned female at birth, and people with a history of mouth ulcers in their family may also find themselves more prone to the condition.
What are the Different Types of Mouth Ulcers?
There are several different types of mouth ulcers, some more common than others. Types of mouth ulcers include:
Minor Ulcers: These are the most common types of mouth ulcers. Typically caused by damage to the mouth, minor ulcers are small, spherical sores that can appear on their own or in small clusters. These ulcers should heal within 2 weeks
Large Ulcers: A more severe type of ulcer, the large mouth ulcer is deeper and longer than a minor ulcer, often measuring over 10mm. These mouth ulcers can take a few weeks, or even a month to heal, and may leave your mouth scarred
Infections/Herpes: Infected mouth ulcers are uncommon but can happen due to certain viral and bacterial infections including herpes simplex. Anaemia and some other blood diseases can also cause mouth ulcers.
What is Recurrent Aphthous Stomatitis?
If you experience a cluster of mouth ulcers that return regularly, you may be experiencing a condition called Recurrent Aphthous Stomatitis also known as RAS or canker sores. The cause of RAS is not fully understood, but experts believe that stress, allergies, trauma in the mouth, nutritional deficiencies and genetics can all cause the condition.
If you live with RAS, you will experience 3-6 episodes of sores per year, but severe versions of the condition may result in an almost constantly ulcerated mouth.
For those with RAS, caring for your bodily and oral health is vital. Though determining the exact cause of the condition is difficult, a balanced diet that contains healthy levels of necessary vitamins is an important way to potentially reduce your condition’s severity. Using gentle but effective mouth-cleaning products is also vital to keep existing sores clean and non-infected.
Mouth Ulcer Treatment
Though mouth ulcers can be painful, and make eating or drinking uncomfortable, they tend to clear up on their own within one or two weeks. There is no set way to remove mouth ulcers, so if you are interested in how to cure a mouth ulcer in one day or less, then you will need to adjust your expectations.
There are however ways in which you can speed up the healing process of mouth ulcers. If you are wondering how to cure mouth ulcers fast, the following steps could help:
Keep your mouth clean with effective and gentle products
Eat softer, milder foods
Reduce stress and anxiety levels
Avoid spicy, acidic, or salty foods and drinks
Use a mouth rinse containing salt and baking soda
Apply ice to the ulcer
Visit your dentist and dental hygienist regularly
If you experience a mouth ulcer that lasts longer than 3 weeks, is extremely painful, or reoccurs regularly, see your doctor as your ulcer may be a sign of an underlying condition.
How to Prevent Mouth Ulcers?
Ulcers in the mouth can be unpleasant and painful, so preventing them is important for regular sufferers. There are no guaranteed ways in which you can prevent mouth ulcers, but several lifestyle and diet changes can have a positive effect and reduce the likelihood of mouth ulcers recurring.
If you are wondering how to prevent mouth ulcers, the following methods could help reduce your susceptibility to ulcers:
Using a high-quality toothbrush can limit damage to the oral mucosa lining and lower your risk of a trauma-based mouth ulcer
Ensuring you eat a balanced diet rich in necessary vitamins (A, C, and E) to speed up the healing process and reduce your risk of diseases in future
Maintaining good oral hygiene through consistent brushing and daily flossing
Regularly visiting the dentist to check your oral health
Unfortunately, there is no way to completely prevent ulcers, and if you were assigned female at birth, have a family history of the condition, or are a sufferer of RAS, you may find it difficult to prevent ulcers in the mouth with at-home treatments.
Oral health is, however, a vital part of preventing mouth ulcers, and to achieve good oral care, you need products that you can trust and should be seeking regular medical attention to give you the best chance of preventing contracting mouth ulcers
Keep Your Mouth Clean with Oral-B
Mouth ulcers can be painful and frustrating, especially when they occur frequently - a condition known as Recurrent Aphthous Stomatitis (RAS). While the exact cause is not always clear, factors like stress, poor sleep, mouth trauma, allergies, and nutritional deficiencies can all contribute. You can treat mouth ulcers at home, through warm water and salt rinsed in the mouth, or with honey and aloe vera. You can also get over the counter medical treatment but if issue persist you should see your doctor or dentist.
It’s essential to take a holistic approach: support your body with a nutrient-rich diet, manage stress, and maintain excellent oral hygiene.
Oral-B is committed to helping you build healthy habits - and the Oral-B iO Series are at the forefront of that mission. With its advanced iO technology, this brush offers superior cleaning compared to manual brushing, while also being gentle on sensitive areas. And don’t forget — regular dental check-ups are key to catching underlying issues early. Combine professional care with daily use of the iO Series for your healthiest mouth yet.
FAQs
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Sources
About Our Medical Reviewers
Dr Robert Lee is a dentist with more than thirty years of experience in the industry. Graduating from the University of Sydney with a Bachelor of Dental Surgery and from the University of New South Wales with a Master of Business Administration, Robert’s career has taken him all over the world – from Australia to Germany to his current position in Chicago, where he is the founder of Denticus Inc., offering strategic dental consulting. Robert has previously worked for Procter & Gamble as the Director of Professional Scientific Relations in both the Cincinnati and Sydney offices, being responsible for external relations and scientific exchange with leading professional associations and industry thought leaders. He was also responsible for all technical and scientific training for the professional teams in North America and Australia. Robert has been assisting the team at Oral-B by fact-checking and reviewing our blogs on dental health.
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