Mouth ulcers
Mouth ulcers are small, painful sores inside the mouth, on the gums, tongue or inside of the cheeks and lips. The common type (aphthous ulcers) is round or oval, white or yellow with a red edge, and heals by itself in 1 to 2 weeks. They are not contagious. An ulcer that does not heal within 3 weeks must be checked by a doctor or dentist.
Symptoms
- One or more painful round sores inside the mouth
- White, grey or yellow centre with a red border
- Pain when eating, drinking or brushing, especially with salty, spicy or sour food
- Tingling or burning before the sore appears
- In children with viral infections, many sores with fever and drooling
Causes
- Biting the cheek, a sharp tooth, a rough denture or brushing too hard
- Stress, tiredness or hormone changes around periods
- Lack of iron, vitamin B12 or folic acid
- Viral infections such as cold sores or hand, foot and mouth disease
- Some toothpastes, foods or medicines
- Less often, illnesses of the gut or immune system
Prevention
- Use a soft toothbrush and brush gently
- Have sharp teeth or rough dentures fixed by a dentist
- Eat a balanced diet with iron-rich foods, fruit and vegetables
- Avoid foods that seem to trigger ulcers
- Manage stress and get enough sleep
Treatment
- Most ulcers heal on their own within 1 to 2 weeks
- Rinse with warm salt water several times a day
- Avoid spicy, salty, sour and very hot food until healed
- Pain-relieving gels or mouthwashes from the pharmacy
- Paracetamol for pain if needed
- Treatment of any deficiency, such as iron or vitamin B12, found on blood tests
Common questions
Are mouth ulcers caused by "heat" in the body?
No. Ulcers are usually caused by injury, stress, low iron or vitamins, or viruses, not by "hot" or "cold" foods. A balanced diet helps, but avoiding particular foods is only useful if they clearly trigger your ulcers.
Can I spread mouth ulcers by sharing a cup?
Common aphthous ulcers are not contagious. Cold sores caused by the herpes virus can spread, so do not share cups or kiss children while you have a cold sore.