What's The Difference Between A Canker Sore And A Cold Sore?

Many people get canker sores and cold sores mixed up, and it is not hard to understand why. The terminology is similar, and both terms refer to an uncomfortable sore generally in or on the mouth. But in almost every other way, canker sores and cold sores could not be more different.

Cold sores are small blisters that may appear on the mouth, lips, eyes, or genitals (per New York State Department of Health). They are caused by herpes simplex virus (HSV), which has several different strains. Cold sores that appear on the face are generally caused by HSV-1. Unlike its counterpart HSV-2, HSV-1 is often not spread by sexual contact. In fact, most people contract HSV-1 during childhood. According to Healthline, children can acquire HSV-1 from kissing or sharing straws or eating utensils with family members who have the virus. This is not uncommon, as 70% of American adults have HSV-1 (per New York State Department of Health), and they are able to spread the virus at any time, even when they don't have an active outbreak.

Unlike canker sores, cold sores typically develop outside the mouth, often in groups (per Healthline). Cold sores often cause redness, and they may tingle or burn and eventually break, resulting in a scab.

Perhaps the biggest difference between cold sores and canker sores is that canker sores are not contagious, as they are not caused by a virus (per Mayo Clinic). Instead, they are often caused by a minor injury inside your mouth that may occur if, for example, you brush too hard or accidentally bite your tongue. Other possible causes include food sensitivities (especially to acidic foods) or toothpastes with sodium lauryl sulfate. Canker sores may also be caused by food allergies, vitamin deficiencies, and emotional stress. Due to hormonal shifts, women may also be more vulnerable to canker sores during menstruation.

Canker sores are small round lesions, typically with a white center and a red border. They only develop inside the mouth, and may even appear on the tongue. They are often painful and can make it difficult to speak or eat, but they generally clear up on their own within a week or two (per Cleveland Clinic).