Intro
A form of the herpes simplex virus called HSV-1 causes cold sores. Cold sores usually form on or around the lips.
An untreated cold sore usually lasts 8-10 days, but can remain for up to two weeks. It typically progresses through five distinct stages.
Learn more about cold sores
Find out more about herpes
Day 1
Tingle stage
This is when you'll feel those first few symptoms, which typically only last for several hours. Your skin could feel like it's tight and itchy, or you may experience
a burning or tingling sensation. This is a sign that the HSV-1 virus is reactivating.
TIPS
Treatment can be started at the first tingle.
What are the first symptoms on your mouth or lips?
Pain or burning
Soreness or tenderness
Pain or burning: You most likely have a cold sore.
Soreness or tenderness: This is usually minor and can be the first sign of a pimple.
TIPS
Treatment can be started at the first tingle.
Days 2-4
Blister stage
This is when you first see the blister developing. The affected area becomes red and swollen and eventually fluid-filled blisters develop containing millions of virus particles. You’ll probably see a group of small, painful lumps that may multiply or grow. The surrounding skin may become red and swollen.
TIPS
Cold sores are contagious even after developing a blister.
Where are the blisters?
Inside my lips
Outside my lips
Inside: You might actually be experiencing a mouth ulcer. These tend to appear as a sore or tender white/yellow patch. They can be found anywhere inside the mouth. Uncommonly, cold sores can occur inside the mouth. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
Outside: It is very likely this is a cold sore. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
Cluster: If you have a cluster of small, softer blisters filled with clear fluid,
it is more likely to be a cold sore. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
One: If the blister is fairly firm, it is more likely to be a blemish. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
Clear. Cold sores are generally clear, as they are full of fluid. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
Coloured.
Cold sores are generally clear. Pimples tend to be red and/or yellow as they contain skin oils and bacteria. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
TIPS
Cold sores are contagious even after developing a blister.
Day 4
Ulcer stage
This can be the most painful stage as the blisters burst and a shallow ulcer (open sore) develops. You may also see a red ring of inflammation around the affected area.
TIPS
This stage can be very painful.
Where is the redness on your lips?
Large area
Specific spot
Larger area. The redness is not centred around a specific spot. Intense dryness can extend beyond the lip with irritation, pain
and possibly splitting or bleeding. If this is the case, you may have chapped lips. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
Specific spot. It’s likely you have a cold sore rather than chapped lips as cold sores usually appear in clusters. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.
TIPS
This stage can be very painful.
Days 5-8
Scabbing stage
This is when your cold sore dries out and forms a yellow/brown scab. Underneath the scab, wound healing of the sore takes place. As your scab shrinks, it may leave you with painful cracks that are prone to bleeding. You may also experience itching and burning.
TIPS
Don’t peel off the scab as you could damage the new, delicate skin and may leave a scar. Let the scab fall off naturally.
TIPS
Don’t peel off the scab as you could damage the new, delicate skin and may leave a scar. Let the scab fall off naturally.
DAYS 8-10
Healing stage
As your scab starts to come off, you may notice some dry flaking and residual swelling. Your skin may also remain slightly pink or red.
TIPS
If your cold sore persists for longer than 10 days, consult your healthcare professional for advice.
TIPS
If your cold sore persists for longer than 10 days, consult your healthcare professional for advice.