Caused by the once-dormant chickenpox virus
(HealthDay News) -- Shingles is caused by the herpes zoster virus, the same one that causes chickenpox.
After chickenpox subsides, the virus becomes inactive (dormant), until an unknown factor triggers its reemergence as shingles-- a painful, blistering rash.
The U.S. National Library of Medicine says you're more likely to develop shingles if you're 60 or older, had chickenpox before you were 1 year old, and have a condition that's caused a weakened immune system.
The agency says these symptoms are typical of shingles: