Cold Sores

Cold sores are a common oral infection caused by the Herpes Simplex Virus. This infection is a painful fluid-filled blister usually in the area where the lip joins the skin. Cold sores usually flare up when your body is already ill with a cold virus. They are contagious when the blister is present. To prevent spreading cold sores, avoid touching, squeezing, or pinching the blister, and wash your hands frequently.