What are cold sores and how do you get them?

Viral : Cold sores or "fever blisters" are tiny, fluid-filled blisters that occur on and around your lips. They are caused by the herpes simplex virus (hsv-1). They are highly contagious. And have no cure. They can be treated with topical creams or oral medications to reduce the severity of the outbreak. They are activated by physical or psychological stress, sunlight and high altitude, fever, menses.

Herpes simplex 1: Cold sore are recureent herpetic lesions, they are viral in nature and most people in the United States are exposed to this virus at a young age.

Contagious virus: People contract oral herpes by touching infected saliva, mucous membranes, or skin. Because the virus is highly contagious, most people have been infected by at least 1 herpes subtype before adulthood. The virus enters your skin or mucous membrane and reproduces. During this stage, oral sores and other symptoms, such as fever, may develop, or it may remain dormant and may reactivate later on.