Cold sores are painful lumps or blisters on the face. They're caused by a virus and are very contagious.
A cold sore usually starts with a tingling, itching or burning feeling. Over the next day or 2, a painful lump or blister will appear on your face.
Treatments for cold sores include antiviral creams and cold sore patches you can get from a pharmacy.
Page last reviewed: 04/07/2017
Next review due: 04/07/2020