Mouth Ulcer

A mouth ulcer is a small round wound in the mouth. It often appears as a grayish yellow base surrounded by a red circle of swollen tissue. Mouth ulcers often make eating and talking uncomfortable. Mouth ulcers that keep coming back may be linked with digestive or immune system problems. 

Mouth ulcers are usually caused by: 

•  Local injury (e.g. biting the inside of cheeks or lips, or injury caused by tooth-brushing) 
•  Lack of certain nutrients such as iron, folate, or vitamin B₁₂ 
•  Stress or hormonal changes 

What you can do 

In most cases, mouth ulcers should recover after a few days. However, the following can help: 

•  Avoid spicy or acidic foods that may irritate the ulcer 
•  Use salt water or antiseptic gargles 

When to see a doctor 

•  If symptoms do not improve after seven days of treatment with topical medicine 
•  If you do not use any medicine and the mouth ulcer does not heal within 14 days 
•  If the symptoms worsen during self-treatment 
•  If you have fever, rash, or swelling  
•  If you have mouth ulcers very often 

How to prevent mouth ulcers 

•  Increase the intake of nutrients like iron, folate or vitamin B, through food or supplements 
•  Do relaxation exercises to reduce stress 
•  Avoid food that have sharp edges like potato chips that may cause injury to your mouth 
•  Go for regular dental check-up and maintain good oral hygiene 
•  Use soft bristle toothbrushes

Updated in Jan 2024