Where do cold sores come from?

Cold sores are caused by the herpes simplex virus type 1 (HSV-1). HSV-1 is a very common virus, and most people are infected with it by the time they are adults. The virus can be spread through contact with infected saliva or skin, and it can also be spread through sharing personal items such as toothbrushes or razors.

Once a person is infected with HSV-1, the virus remains in their body for life. The virus can reactivate from time to time, causing cold sores to appear. Cold sores are typically small, painful blisters that form on the lips or around the mouth. They can also appear on the nose, cheeks, or chin.

Cold sores usually heal within 2 to 4 weeks. There is no cure for HSV-1, but there are treatments that can help to reduce the symptoms of cold sores and prevent them from recurring.