What are Mouth Ulcers and How to Treat Them?

Mouth ulcers (also known as mouth sores, or canker sores), are small lesions that may develop within the oral cavity. They can appear on the inside of the cheeks, the gums, lips and even on the tongue.

Mouth ulcers happen when there is a break in the skin or mucous membrane epithelium of the oral cavity, causing a white/greyish colour accompanied by a strong red border.

They can be quite painful and extremely disturbing, especially if they interfere with eating, but there are some techniques that you can follow to help reduce pain and to enhance healing time.

What are Mouth Ulcers and How to Treat Them

What causes mouth ulcers?

Most mouth ulcers present with no apparent cause and are nothing to be worried about, and simply regress on their own over time.

However, a mouth ulcer that persists for more than 3 weeks may warrant further investigation, in order to make sure that it’s nothing more serious (1).

Although the exact cause of mouth ulcers is not clear yet, here a few common known causes:

  • Injury or Trauma

Injury to your mouth and oral tissue may cause an ulcer to develop.

This includes any sort of mechanical trauma that may have accidentally injured the lining of your mouth, such as accidental biting, hard brushing, or even injury from dental work.

  • Genetic

If there is a history of mouth ulcers in your family, then there is a very high chance that you may also develop mouth ulcers too. Genetics plays a strong role in the cause of mouth ulcers.

  • Stress and Hormonal changes

A lot of stress can cause hormonal changes and even a weakened immune system, for this reason studies have shown that stress can actually be a cause of mouth ulcers (2).

Hormonal changes due to menstruation or pregnancy can also cause mouth ulcers.

  • Poor oral hygiene

In addition to so many other dental problems including cavities and gum disease, skipping brushing your teeth and flossing, or not maintaining proper oral hygiene can also cause gum and mouth ulcers to form.

  • Aggressive tooth brushing

In addition to causing tooth wear and recession, brushing your teeth too strongly or quickly may cause an injury and consequently an ulcer to form.

  • Food sensitivity

Mouth ulcers can also be caused by sensitivity to certain acidic foods such as citrus fruits, pineapples, and strawberries.

Additionally, very hot and spicy food has been reported to cause mouth ulcers in some people.

  • Nutritional deficiencies

Certain nutritional and vitamin deficiencies such as iron, zinc, vitamin B-12 and folate all increase the risk of developing mouth sores and ulcers.

  • More serious medical conditions

There are several systemic and medical disorders and conditions that can cause mouth ulcers to form. The most important of these are:

  • Diabetes mellitus
  • HIV and Aids
  • Celiac disease
  • Inflammatory Bowel Disease
  • Behcet’s disease

How to treat mouth ulcers?

The overall goal of treating mouth ulcers is to reduce pain, enhance healing, and prevent recession of the ulcer or sore (3).

A mouth ulcer is considered as a self-limiting disease, which means that it goes away on it’s own in around ten days or so, however; if you get mouth ulcers often or in very sensitive and painful places in your mouth, then below are some tips that you can help to reduce pain and help quicken the healing time:

  • Ensure proper oral hygiene

Brush your teeth gently twice a day and floss once a day.

  • Rinsing and gargling your mouth with saltwater

  • Avoid trigger foods

Avoid hot, spicy, and acidic foods and drinks (especially citrus fruits like lemons).

  • Use a mouthwash

The best time to use a mouthwash to aid in mouth sore healing is right before you go to sleep. This makes sure that the material is exposed to the ulcer for as long as possible.

  • Use a topical anesthetic gel

This will help to reduce the inflammation and pain associated with the mouth ulcer

  • Improve your diet or consider taking nutritional supplements

Try to improve your nutritional level by eating a healthy and balanced diet, or consider getting nutritional supplements to guarantee adequate levels of folic acid, iron, zinc, and vitamin B-12.

  • Consider home natural remedies

There is no clear evidence whether or not these work, but some people have reported that chamomile tea, honey turmeric, and coconut oil have helped to soothe the pain and promote healing.

I would advice steering away from any home remedies that require acidic substances such as vinegar, lemons or oranges. These will be extremely painful and may even make the ulcer worse.

If your mouth ulcer is due to a vitamin C deficiency, consider taking vitamin C supplements instead.

When to see a doctor for mouth ulcers?

As mentioned earlier, any mouth ulcer that has been present for more than 3 weeks requires an immediate professional look.

If the mouth ulcers develop too often are extremely painful or disturbing you too much that you find yourself unable to eat or drink properly, then considering visiting your dentist.

Mouth ulcers that developed after you have begun taking a new medication may require a professional look to make sure that the ulcers aren’t a side-effect of the new medicine. If this is the case, you may need to get an alternative medicine.


Written by Dr. Khaled Mahmoud

Khaled Mahmoud completed his dental education and obtained his Bachelor of Dental Surgery (BDS) in 2017. His interests lie in cosmetic dentistry and non-surgical facial aesthetics. He is active in dental research, contemporary cosmetic materials and techniques, and has been a member of numerous public health outreach programs.