Cold sores are an infection that affects the mouth and lips. They are caused by the herpes simplex virus. They appear as a cluster of blisters, usually red, and may have some scabbing around the edges. Cold sores are caused by the herpes simplex virus, and most treatments focus on preventing outbreaks from happening.   What Causes Cold Sores? Cold sores occur when the human body is exposed to a virus closely related to Herpes Simplex Virus. The virus usually arrives in contact with an open sore or through saliva and can reside on the lips for several hours or days before it is transmittedRead More →