Shingles is caused by the varicella-zoster virus - the same virus that causes chickenpox.

Anyone who's had chickenpox may develop shingles.

After you recover from chickenpox, the virus can enter your nervous system and lie dormant for years.

Eventually, it may reactivate and travel along nerve pathways to your skin - producing shingles.
The reason for the encore is unclear.
But it may be due to lowered immunity to infections as you grow. Shingles is more common in older adults and in people who have weak immune systems. ... to this page ...