HEALTH

If the sore has a white or gray base with red border, you have a canker sore. Canker sores are caused by almost anything – braces, brushing too hard, biting the inside of your mouth.

“If a canker sore doesn’t go away in four to seven days or constantly reappears, you might have a poorly functioning immune system or a vitamin deficiency,” says dentist Dr. Sinaida Kniter. Rinse with an anti-microbial mouthwash to reduce irritation. Try Rembrandt’s Canker Pain Relief Kit or Canker Prevention Toothpaste if you’re prone to outbreaks.

Meantime, avoid spicy and acidic foods, and keep up good brushing and flossing habits to ward off bacteria.