What is Cold Sores?

Cold sores are small, painful, fluid-filled blisters or sores that appear on the lips, mouth, or nose that are caused by a virus. The sores can be painful and usually last a few days. Unlike most viral infections, the cold sore virus is not completely eliminated by the body defenses. For this reason, cold sores often recur. Picture of cold sores; SOURCE: CDC/Dr. Hermann

Source: http://www.emedicinehealth.com