Reviewed in August 2019 by Lane Wells, Registered Nurse in our Health at Hand team.
Shingles is caused by the reactivation of the varicella-zoster virus, which is the virus that causes chickenpox. After you have had chickenpox the varicella-zoster virus lies dormant (inactive) inside your body. It can become reactivated at a later stage and cause shingles.
While it is not known exactly why the virus is reactivated, it is thought to be linked to having lowered immunity (protection against infection and diseases). Shingles itself cannot be passed from one person to another. However, the virus that causes shingles, the varicella zoster virus, can be spread from a person with active shingles to another person who has never had chickenpox.
In such cases, the person exposed to the virus might develop chickenpox, but they would not develop shingles. The virus is spread through direct contact with fluid from the rash blisters caused by shingles. A person with active shingles can spread the virus when the rash is in the blister-phase, however a person is not infectious before the blisters appear. Once the rash has developed crusts the person is no longer contagious.
It’s also worth bearing in mind that shingles is less contagious than chickenpox and the risk of a person with shingles spreading the virus is low if the rash is covered. I hope this information will be of use.
You may also be interested in...
Shingles - NHS factsheet
Chickenpox - NHS factsheet
Shingles and scarring - AXA Health
