You can get shingles only if you have already had chickenpox. Sometimes people think they haven't had chickenpox, but they may have been too young to remember having the disease, or they may have had such a mild case that it wasn't diagnosed at the time.

The herpes varicella-zoster virus that causes chickenpox retreats to nerves located near the spine, where the virus remains dormant until it re-emerges as shingles, often during a period of stress or weakened immunity.