Cold sores, also called fever blisters or recurrent herpes labialis, are caused by the herpes simplex virus, and they’re contagious. HSV-1 is the virus that most commonly causes cold sores on the lips or face. It is often transmitted in childhood through kissing, but can be transmitted at any age. Though you can’t cure or prevent cold sores, you can take steps to reduce their frequency and to limit the duration of an occurrence.

Signs and symptoms of cold sores include:

  • Small, painful, fluid-filled blisters on a raised, red, painful area of your skin
  • Pain or tingling, called the prodrome, often precedes the blisters by one to two days
  • Usual duration of seven to 10 days

Cold sores are a type of facial lesion that are found either on the lips or else on the skin in the area immediately adjacent to the mouth. Cold sores are caused by the herpes simplex virus (“type 1” and “type 2).