Canker sores, also known as mouth ulcers, are caused by a variety of factors, although the exact cause is unknown. They can be triggered by stress and anxiety, hormonal changes, minor injuries to the mouth (from dental work, biting the cheek, or brushing too hard), certain food sensitivities, and nutritional deficiencies such as lacking vitamin B12, zinc, folic acid, or iron. Other contributors can include emotional stress, food allergies, and problems with the body's immune system. Canker sores are not contagious and are more common in women and young people.
Key causes include:
- Emotional and physical stress
- Hormonal shifts, especially in women
- Minor mouth injuries
- Dietary deficiencies in vitamins and minerals
- Certain foods like chocolate, coffee, strawberries, nuts, cheese, and spicy or acidic foods
- Immune system issues
Despite these known triggers, the exact biological cause remains unclear.
