What causes canker sores and how can they be prevented or treated effectively?

Canker sores are small ulcers that can form inside the mouth due to various factors like stress, injury, or certain foods. To prevent them, maintain good oral hygiene, avoid trigger foods, and manage stress. Treatment options include over-the-counter medications, mouth rinses, and topical gels to reduce pain and promote healing. Severe cases may require prescription medications from a healthcare provider.