Shingles (herpes zoster) is an outbreak of blisters by the same virus that causes chickenpox, the varicella-zoster virus (VZV). After getting over the chickenpox, the virus remains dormant in the body. Doctors don’t know why the virus suddenly reactivates years later.
It is estimated that one out of every three Americans will develop shingles. Half of the shingles cases occur in people 60 and older.