Mouth Ulcers

Ever had such an aching pain in your mouth it even hurt to talk and eat? Mouth ulcers, also known as canker sores or aphthous ulcers, are most probably the underlying source of such agony. Swollen around the edges, they are small oval-shaped lesions that are generally harmless, albeit painful, and merely a minor discomfort for the vast majority of us. 

Unfortunately, this is not always the case. 20-30% of the global population suffers from recurrent aphthous stomatitis (RAS) – a condition in which the patient has several mouth ulcers at once. Here, consulting a medical professional is the best option. These mouth ulcers can be a symptom of a malfunctioning immune system or one of the following diseases:

  • Hand, food, and mouth disease

  • Oral lichen planus

  • Celiac disease

  • Inflammatory bowel disease (IBD)

  • Diabetes mellitus 

  • Bahcet’s disease


With that being said, less extreme cases of mouth ulcers are much more common amongst the general population. 

There are a multitude of uncontrollable causes. This includes hormonal changes (especially during menstruation and pregnancy), diseases (as mentioned previously), genes (those who carry certain genes are more prone to mouth ulcers than others), and vitamin B-12 or iron deficiency. On a less likely note, the action of abruptly quitting smoking is another possible trigger.

In contrast, mouth ulcers also stem from a number of controllable causes, like damaged cheeks due to hot food, braces, or bites. Similarly, anything that irritates the inside of the mouth can lead to the formation of mouth ulcers; for instance, toothpastes that contain sodium lauryl sulphate and toothbrushes that damage the gums can cut the mouth tissue. In terms of food, the overconsumption of acidic foods such as strawberries and trigger foods such as chocolate can also aggravate the tissue over time. Stress and tiredness are typically the average cause of mouth ulcers, alongside the aforementioned physical factors.

There are three main types of mouth ulcers:

Herpetiform Ulceration (HU)

Its name is derived from its resemblance to herpes sores, as this particular type of ulcer occurs in large groups of 10-100, which takes approximately 1-2 weeks to heal. Once it has healed though, it leaves behind no scars.

Screenshot 2020-11-22 at 21.24.26.png

Minor Ulcers

This is the most common type of ulcer – only 2mm-8mm in diameter. As its name suggests, a minor ulcer causes minimal pain. It takes up to about 2 weeks to heal.

Major Ulcers

Major ulcers are notoriously painful: its irregular shape reflects the deep and large cut in the tissue, compared to that of minor ulcers. As it is much more severe, major ulcers take a couple of weeks to heal, and will inevitably leave a permanent scar on the tissue.

major u;.jpg

Most mouth ulcers heal on their own over the course of a few weeks. Thus, it is hard to find a proper treatment for them. There are, however, many ways to speed up the healing process naturally – the most simple being to apply ice or milk of magnesia on the ulcer. Otherwise, there is a range of other methods to treat mouth ulcers as well: placing damp tea bags on it, covering it with a baking soda paste composed of salt, water, and baking soda, or spreading benzocaine products like Anbesol and Orajel on the swollen areas, just to name a few. Nowadays, most people tend to turn to nutritional supplements like vitamin B-6, vitamin B-12, zinc, and folic acid too.

Screenshot 2020-11-22 at 21.58.55.png

By Nichapatr (Petch) Lomtakul and Narin (Estelle) Kim (Year 12 students at Bangkok Patana School)


Wikipedia Contributors (2020). Mouth ulcer. [online] [Accessed 18 Oct. 2020]. Available at:


Fletcher, J. (2018). Everything you need to know about mouth ulcers. [online] [Accessed 18 Oct. 2020]. Available at:


NHS Choices (2020). Mouth ulcers. [online] [Accessed 18 Oct 2020]. Available at:

‌Johnson, S. (2017). What Causes Mouth Ulcers and How to Treat Them. [online]  [Accessed 18 Oct. 2020]. Available at: