
Causes
Cold sores are caused by a virus known as the Herpes Simplex Virus type 1 or HSV-1 for short.
How the virus spreads
Research shows that 80% of general populations are the carriers of HSV-1. Furthermore, almost 90% of people aged over 30 carry the virus. 20% of those infected regularly suffer from outbreaks of cold sores¹. It is believed that HSV-1 is most often contracted during childhood and infancy. Once infected a person can suffer from regular outbreaks of cold sores for the rest of his or her life.
The HSV-1 virus is very contagious. It is usually spread through physical contact such as hugging and kissing but can also be transmitted by sharing a drink. The virus can be spread from the very start of the cold sore outbreak when you feel the tingling, burning or itching right through to the healing stage when the crust finally disappears. The virus can be spread by an infected person, even if they do not show the symptoms. Although HSV-1 most commonly attacks the lips, nose or chin, it can be passed to other parts of the body including the eyes, fingers and the genitals. Click for advice on how to avoid contamination.
¹"Herpes simplex virus infections", Richard Whiteley and Bernard Roizman, The Lancet, Vol 357, May 12, 2001
The different stages of a cold sore outbreak
(GRAPH DOES NOT FIT)
This graph shows the typical stages of a cold sore outbreak that lasts 12 days. Some outbreaks may be longer or shorter than this
Stage 1 - The tingle stage
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Stage 2 - The blister stage
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Stage 3 - The weeping/ulcer stage
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Stage 4 - The scab/crusting stage
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Stage 5 - Healing stage
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