See the Colgate online article about cold sores and fever blisters to learn what causes fever blisters as well as cold sores and other types of viruses. Now it is time to identify what may cause your cold sore outbreaks, so you'll have one more weapon in your arsenal. Remember, not everyone's cold sore is . Cold sores are common and usually clear up on their own within 10 days. They're. Things you can try; When to get medical help; Treatment from a GP; Causes. Although it's thought that around seven in every ten people carry the virus which causes cold sores, many don't know they have it because it doesn't always . The virus that most commonly causes cold sores is herpes simplex 1, a cousin of herpes simplex 2. However, in a minority of cases, herpes simplex 2 can also .Cold Sores in Nose: Causes, Symptoms, Treatment and Home Remedies What is cold sore? When you battle cold, flu or nasal congestion, the last thing you . Read Bupa fact sheet on cold sores (oral herpes), including symptoms, complications, causes, diagnosis, treatment and prevention. Cold sores are caused by a virus that those infected will carry with them for the rest of their lives. Learn about 10 causes and treatments for cold sores in this article.