Mouth ulcer


Mouth Ulcers & Sores: Symptoms & Treatment

Written By : Generations of Smiles Writers

Reviewed By : Charles Rodgers, DDS

Published: Oct 27, 2021

In This Article
Mouth ulcers and sores are common issues that plague a significant portion of the population. Perhaps you have already experienced the searing pain they can bring after taking a bite of a particularly acidic fruit or noticed what feels like a mountain protruding from your cheek that impedes the simple pleasures in life, like good food and great conversation. If you’re looking for relief from the discomfort that mouth ulcers and sores bring, it’s important to analyze the symptoms to determine what you’re facing and what the best course of treatment will be.  

What Is a Mouth Ulcer?

A mouth ulcer is a non-contagious lesion in the mouth that is usually quite painful and irritating. For example, imagine you’ve just sat down with a piping hot slice of your favorite pizza…you take a huge bite of the pizza, then, in the midst of your enthusiasm, take a bite out of your cheek. A lesion is formed from the bite, bacteria enter the lesion, and a mouth ulcer is born.

Canker sores are called a “sore” but are actually mouth ulcers with a different underlying cause. Conversely, a cold sore is also called a “sore” but is not a mouth ulcer at all – cold sores stem from a virus, are found outside the mouth (usually on the lips), and are highly contagious.

Mouth sores can be a sign of many things – some as simple as trauma to the mouth, and others as complex as different types of diseases and allergies. They can also be a sign of viral infections such as Oral Herpes, which is caused by the herpes simplex virus. Bacterial infections can also cause mouth sores, especially if one has poor oral hygiene and an open lesion from trauma that bacteria can easily infect.  

What Causes Mouth Sores and Ulcers?

Mouth sores and ulcers stem from a variety of different causes. Mouth sores causes include:
  • Trauma, such as accidental biting, scratching, or damage from orthodontic appliances
  • Viral infections, such as oral herpes
  • Various underlying conditions, such as Aphthous Stomatitis, which can lead to canker sores
  • Allergic reactions and food sensitivities
  • Fluctuations in hormones
  • Different types of diseases such as HIV/AIDS, Behcet’s Disease, and Crohn’s disease, to name a few
  • Burns from acid reflux, hot food and drinks, or highly acidic foods
  • Resurgence of a dormant virus due to a trigger, such as canker sores developing regularly during a high-stress season of life

Mouth Ulcer Symptoms

Mouth ulcers can be found in any part of your mouth, including the tongue, lips, cheeks, gums, or the roof of the mouth. A variety of visual clues indicate the presence of mouth ulcers. They are usually round or oval and can vary in size, typically not exceeding one centimeter in diameter. Mouth ulcers can appear white, gray, yellow, or bright red – or a combination of those colors. The bright red is especially prevalent when there is inflammation present.
Pain and irritation are primary symptoms of a mouth ulcer – it’s likely you will feel it before you see it. If you’ve ever been the victim of a poorly placed papercut, you know that the size of an affliction doesn’t necessarily determine the level of pain it can cause. Unfortunately, a sore located in the mouth is usually being touched by something, which can increase the level of pain. Add to that the pain inflicted by eating, talking, and coming into contact with foreign objects such as braces, and you have the potential for a small lesion that can cause a serious amount of pain.

Treatment for Mouth Ulcers and Sores

Mouth ulcers do not necessarily need treatment – most clear up on their own within a week or two. However, if you’re suffering from ulcers and sores, you’re probably wondering how to cure a mouth ulcer. Most people would like them to heal with as little discomfort as possible, so there are several treatments that can ease the pain during the healing process. Using these treatments may also speed the healing process by reducing the amount of irritation to the mouth sore.
Mouth ulcer treatment options are easy and readily available, such as:
  • Applying a topical numbing treatment such as Orajel or Anbesol
  • Taking a painkiller with anti-inflammatory properties such as Ibuprofen or other NSAIDs (nonsteroidal anti-inflammatory drugs)
  • Using an antimicrobial mouthwash from your local pharmacy
  • If you’re looking for how to cure mouth ulcers fast naturally, there are several types of mouth sore treatments that don’t involve chemicals or harsh ingredients:
  • Do a warm saltwater rinse two to three times a day, as it will promote healing and keep the sore from getting worse
  • Apply milk of magnesia directly to the mouth ulcer
  • Rest damp tea bags on affected areas to ease the pain
  • Use ice to numb canker sores

Prevention of Mouth Ulcers

While you’re looking into how to cure mouth sores in the present, it’s also important to think ahead as to how to prevent mouth ulcers in the future. There are several commonsense ways to prevent recurrences, many of which are just basic principles of self-care that will benefit you on different levels.

The immune system can quickly become compromised when the body is under significant stress. Stress can also act as a trigger for conditions such as Aphthous Stomatitis, for example, which could lead to a flare-up in canker sores. Learn to manage stress in a way that is sustainable and works with the natural rhythm of your life. If you have a high-stress job, practice breathing exercises and relaxation techniques to use on particularly difficult days. Join a spin class, lift weights, take a walk – just get moving! Exercise is great for stress reduction and will help you sleep better, which is a very important factor in the healing process.
Avoid foods that might cause irritation, especially those that are spicy, crunchy, or highly acidic. One slip of the corner of a tortilla chip could dig into your gums and cause a mouth ulcer you’ll have to deal with for days on end! Choose foods that are healthy and part of a balanced diet, ensuring that you get the appropriate vitamins and minerals necessary on a daily basis for your body to be healthy and ready to fight infection.
Other practical tips to prevent mouth ulcers include reducing how much you talk while chewing to avoid accidentally biting yourself or causing a lesion from food digging into the soft tissue of your mouth. Practice good oral hygiene to reduce the number of bacteria in your mouth, which includes keeping up with your regular dental exams and cleanings.


If you would like to get an idea of what type of issue you’re dealing with, here is a brief overview of different types of mouth ulcers and sores:
  • Canker Sore – non-contagious, shallow lesions that develop on the gums or in different areas of the mouth. They can also be referred to as aphthous ulcers and usually stem from a condition called Aphthous Stomatitis.
  • Blister – a lesion that can occur in several different places, both inside the mouth and outside on the lips. Blisters can be a result of a virus, such as the herpes simplex virus, or a variety of other causes, like a canker sore or a mouth burn from excessively hot food.
  • Bump – bumps in the mouth such as mucocele, warts, or the beginning of an aphthous ulcer (canker sore) may be signs of underlying conditions and potentially may need to be evaluated by a professional.
  • Aphthous Ulcer – a canker sore.
  • Cold Sore – highly contagious, caused by a viral infection; also referred to as a fever blister.
  • Herpes – a virus, Herpes Simplex Virus, that causes chronic cold sores.

Find a Dentist Near You to Treat Mouth Ulcers and Sores

While there are many different home remedies that could ease the pain of a mouth ulcer or sore, there are times when it is important to get examined by a professional. If you experience any of the following, it’s time to seek the help of a dentist:
  • A mouth ulcer or sore that doesn’t heal after two weeks
  • A mouth ulcer that has a diameter greater than two centimeters
  • Three or more mouth ulcers present at one time
  • A history of oral cancer, HPV, or other conditions directly related to oral health
  • A history of gum disease
  • A recurring mouth ulcer
  • Unbearable pain from a mouth ulcer or sore
  • A high fever along with mouth sores

If you are experiencing any of these issues, it’s important to see a professional. There is no need to suffer unnecessarily, and early detection is key when it comes to identifying red flags of major health concerns that may be happening beyond your oral health. Dentists are highly trained in determining not only how to treat surface issues but also how to diagnose underlying health issues that could be causing mouth sores and ulcers. If you aren’t an established patient with a dentist and you're asking yourself where to find a dentist near me, use The Smile Generation “Find a Dentist” tool for help finding a capable, caring dentist near you.  


Find your trusted, local dentist today!




Smile Generation blog articles are reviewed by a licensed dental professional before publishing. However, we present this information for educational purposes only with the intent to promote readers’ understanding of oral health and oral healthcare treatment options and technology. We do not intend for our blog content to substitute for professional dental care and clinical advice, diagnosis, or treatment planning provided by a licensed dental professional. Smile Generation always recommends seeking the advice of a dentist, physician, or other licensed healthcare professional for a dental or medical condition or treatment. 

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