Cold sores are caused by infection with the herpes simplex virus, most commonly herpes simplex virus type 1 (HSV-1), and less commonly type 2 (HSV-2). You get cold sores by close contact with someone who has the virus, such as through kissing, skin-to-skin contact, or sharing items like eating utensils, towels, or toothbrushes with an infected person
. The virus enters through the skin or mucous membranes, often around the mouth, and then stays dormant in the body. It can reactivate later due to triggers such as stress, illness, fatigue, hormonal changes (like menstruation), sun exposure, or skin trauma, causing cold sores to appear
. Cold sores are contagious from the moment you feel the first tingling or itching until the sores have completely healed. The virus spreads through direct contact with the sores or saliva of an infected person
. In summary, you get cold sores by coming into direct contact with the herpes simplex virus from an infected person, usually through kissing or sharing personal items, and the virus can reactivate later to cause outbreaks.
