Cold sores, sometimes called fever blisters, are small, fluid-filled blisters. They can form anywhere on the face, but they are most common around the mouth or lips.

They often start as an itching or tingling feeling, followed by a blister about a day later. When the blister breaks, a yellow crusting appears at the site.

You might find them painful and even embarrassing. Luckily, cold sores go away in a week or two and don’t cause scarring. 

Cold sores are caused by the herpes simplex virus type 1 (HSV-1), and about two-thirds of people under age 50 may have it, according to the World Health Organization (WHO). So it’s very possible to have the virus but not have symptoms. 

Take the quiz below to test your knowledge and learn a few key tips and tricks on managing cold sores.