Shingles, also known as herpes zoster, is an infection of a nerve and the skin around it. It’s caused by the varicella-zoster virus, which also causes chickenpox.
It’s estimated around one in every four people will have at least one episode of shingles during their life.
Most people have chickenpox in childhood, but after the illness has gone the varicella-zoster virus remains inactive (dormant) in the nervous system.
The immune system keeps the virus in check, but it can be reactivated later in life and cause shingles.
It’s possible to have shingles more than once, but it’s very rare to get it more than twice.