Canker sores often seem to pop up out of nowhere and, once you have them, they’re often painfully hard to ignore — especially when you try to eat or even talk. So what, exactly, are canker sores? They ...

Canker sores are bacterial, non-contagious infections that occur on the gums, inner lips, inside the cheeks and sometimes on the tongue. They are usually red and round with a white center. Most canker ...

Roll your tongue around your mouth, and you might feel a sting from a new tender spot. A tiny, unwelcome crater of pain, a red circle of fire tucked against your cheek. It feels worse with every ...

A canker sore—a painful white ulcer inside the mouth—might be brought on by stress. Or the wrong toothpaste. Or certain foods: tomatoes, peanuts, cinnamon. Or an iron deficiency. Or an allergy. Or a ...

Canker sores are vexing and common. The reason they occur isn’t clear, but your toothpaste could be a factor. An ingredient often used to make toothpaste foamy, sodium lauryl sulfate (SLS), has been ...