Cold sores are common and usually clear up on their own within 10 days. But there are things you can do to help ease the pain.
Check if it's a cold sore
A cold sore usually starts with a tingling, itching or burning feeling.
Over the next 48 hours:
Small fluid-filled blisters appear.
The blisters can appear anywhere on the face.
The blisters burst and crust over into a scab.
Cold sores should start to heal within 10 days, but are contagious and may be irritating or painful while they heal.
Some people find that certain things trigger a cold sore, such as another illness, sunshine or periods.
When it's not a cold sore
How long cold sores are contagious
Cold sores are contagious from the moment you first feel tingling or other signs of a cold sore coming on to when the cold sore has completely healed.
A pharmacist can help with cold sores
A pharmacist can recommend:
You can buy electronic devices from pharmacies that treat cold sores with light or lasers.
Some people find these helpful, but there have not been many studies to find out if they work.
If you regularly get cold sores, use antiviral creams as soon as you recognise the early tingling feeling. They do not always work after blisters appear.
Things you can do yourself
Cold sores take time to heal and they're very contagious, especially when the blisters burst.
Do not kiss babies if you have a cold sore. It can lead to neonatal herpes, which is very dangerous to newborn babies.
See a GP if:
Treatment from a GP
A GP may prescribe antiviral tablets if your cold sores are very large, painful or keep coming back.
Newborn babies, pregnant women and people with a weakened immune system may be referred to hospital for advice or treatment.
Why cold sores come back
Cold sores are caused by a virus called herpes simplex.
Once you have the virus, it stays in your skin for the rest of your life. Sometimes it causes a cold sore.
Most people are exposed to the virus when they're young after close contact with someone who has a cold sore.
It does not usually cause any symptoms until you're older. You will not know if it's in your skin unless you get a cold sore.