What is a cold sore?

Cold sores, also known as fever blisters, are caused by the HSV-1 virus and are very common. They can be easy to recognise as they usually appear as red bumps or blisters around the lips and mouth. You can find out more about cold sores here.

About Cold Sore
About Cold Sore

What causes cold sores?

Cold sores are caused by HSV-1, a form of the herpes simplex virus. In fact, up to 80% of the global population has the HSV-1 virus because it’s so contagious. Once infected, the virus never leaves the body.

Most people aren’t exactly sure when they first encountered HSV-1. It’s usually contracted in early childhood where it may not appear as a visible cold sore.

What happens when I get a cold sore?

For the majority of people, HSV-1 remains inactive throughout their lives and they may never know they have the virus. Around 1 in 3 people will experience recurrent infections. The HSV-1 virus ‘wakes up’, infects the cells in or around the lip or mouth and causes a visible and contagious sore. Symptoms of cold sores usually occur after something has triggered the virus, like a run-down immune system or cold, dry weather leading to dry, chapped lips.