Cold sores are small blisters that form around the mouth that are clear and filled with fluid. Cold sores are caused by the herpes simplex virus which lives inside nerve tissue. It is estimated that 80% of the population carry the virus and 60 million people have outbreaks once or more per year. Cold sores are also known as fever blisters or Herpes Simplex or HSV1, this is not the same as genital herpes.


