Causes of mouth ulcer

In many cases, the real reason for a mouth ulcer is challenging to identify.
Based on the nature of the trigger, the causes of mouth ulcers are categorized as below

Lifestyle Reasons

You can develop a mouth ulcer in the initial days after you quit smoking.

Some women get a mouth ulcer due to hormonal changes during their menstrual cycle.

Research has shown that emotional stress, anxiety and lack of sleep too can trigger a mouth ulcer.


You can get a mouth ulcer if you accidentally bite the inside of your mouth while eating or talking.

You can get it if you brush too hard using a new brush.

Some toothpaste or mouthwashes, which contain sodium lauryl sulphate, can cause mouth ulcer.

In older adults, a poorly fitted denture can hurt the gums, causing a mouth ulcer at that site.

In people who use braces, the constant touch of the braces can cause mouth ulcers.


Certain food items such as spicy food, caffeine, and citrus foods can damage the inside lining of your mouth and give you a mouth ulcer. Moreover, eating these foods can cause a sharp sensation if you already have a mouth ulcer.

Eating hard foods like nuts in a hurry can hurt or bruise the lining of your mouth, leading to a mouth ulcer.

Medical Conditions

In rare cases, some medical conditions too can cause a mouth ulcer. 

Sometimes, mouth ulcers can be caused by some bacterial or viral infections such as cold sore virus, chickenpox, and hand, foot and mouth disease.

Deficiency of essential vitamins such as vitamin B12, folic acid or iron has been found to cause mouth ulcers.

Some medications used to treat pain, heart diseases, cancer, etc. have been reported to cause mouth ulcers.

Ulcers in the mouth are a common symptom of underlying conditions and diseases such as crohn’s disease, weak immunity, celiac disease, HIV/AIDS, and certain cancers.

Mouth ulcers may also be hereditary.
Around 40% of people with recurrent mouth ulcers report that it runs in their family.