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.
It is not known exactly why the virus is reactivated, but it is linked to having lowered immunity (protection against infection and diseases).
Your immunity to illness and infection can become lowered if there is a problem with your immune system (the body’s natural defence system). This can happen as a result of:
However, young people who appear otherwise healthy can also sometimes develop shingles.
It is not possible to catch shingles from someone else with the condition, or from someone with chickenpox.
However, it is possible for someone who has never had chickenpox to catch it from someone with shingles, as the shingles blisters contains the live virus.
In the UK, chickenpox is so common during childhood that 9 out of 10 adults have already had it and will not be at risk from someone with shingles.
The blisters that develop as a result of shingles contain virus particles. If you have not had chickenpox before, you can catch it from direct contact with the fluid from the blisters of someone who has shingles, or from something that has the fluid on it, such as bed sheets or a towel.
If you have shingles, you are contagious until the last blister has scabbed over. This will usually occur after about 10 to 14 days.
If you have the shingles rash, do not share towels or flannels, go swimming, or play contact sports. This will help prevent the virus being passed on to someone who has not had chickenpox.
You should also avoid work or school if your rash is weeping (oozing fluid) and cannot be covered.
Chickenpox can be particularly dangerous for certain groups of people. If you have shingles, avoid:
Once your blisters have dried and scabbed over, you are no longer contagious and will not need to avoid anyone.
SOURCE: NHS UK