Canker and cold sores share a few common traits. They both occur in and around the mouth, and both cause discomfort. Unsure which type you have? Here is a description of each:
Canker sores are not contagious and generally appear inside your mouth. They are caused by bacteria and can occur after a shock, such as biting the inside of your cheek or poking your gums unintentionally. Canker sores generally last one to two weeks.
Cold sores are contagious and appear outside your mouth, generally around your lips. They are viral and caused by the herpes simplex virus. This is not the same virus that causes genital herpes, don’t worry! These small, clear blisters generally last for one week.
Many over-the-counter medications can soothe the pain and discomfort of your canker or cold sores.