Mouth Sores


We all know how annoying mouth sores can be. Your lips and gums are sensitive, and the sores make it hard for you to eat and talk. They can also be slow to heal. Let's learn about common types of mouth sores and what they mean for you.

Cold sores

If you have a small blister on or near your lip, you likely have a cold sore. We also call this a "fever blister." You can have one, or several in a cluster. These sores are caused by the herpes simplex virus. They spread through kissing and close contact. They tingle, itch and burn, and then go away after a few days or weeks. There is no cure for them, but you can ease the discomfort with topical medications. Cold sores may flare up occasionally throughout your life. Antiviral medications help heal them more quickly, and help keep them away.

Canker sores

If you have a sore inside your mouth, it may be a canker sore. These ulcers can be small or large, and may be white with a red border. They can form inside your lips, on or under your tongue, on your gums, on your cheeks and on the roof of your mouth. We don't always know why they form. They may be linked to things like stress, hormones, diet, injury, or sensitivity to food or toothpaste. They may also be linked to certain conditions and diseases. Canker sores don't spread from person to person. These sores may take from one to six weeks to heal. If it's a large or deep sore, it may leave a scar.


If you have a sore that doesn't heal, that bleeds, or that causes thickening or lumps in the tissue of your mouth, don't ignore it. These are signs of cancer. Schedule an appointment with your dentist or your doctor to make sure you get the care you need.