Canker sores may be small, but they can make everyday things — like sipping coffee, eating lunch, or brushing your teeth — surprisingly painful. And while most clear up on their own, understanding what triggers them can help you avoid the discomfort and cut down on future flare-ups. We asked Syed Hussain, MD, medical director at Hartford HealthCare Urgent Care about what causes canker sores.
What is a canker sore?
Canker sores are small, shallow ulcers that form inside your mouth, usually in locations like your inner cheek, tongue or gums. They usually look like round or oval spots with a white or yellow center, and a red border. They’re not the same as cold sores, which can be confusing.
“Cold sores are contagious, typically come with fever or cold-like symptoms, and appear as painful blisters on the upper lip,” says Dr. Hussain. Most canker sores clear up within a week or two, and they’re usually not contagious. But knowing what sets them off, and how to ease the pain, can make a big difference.
