Shingles is a reactivation of the same virus that causes chicken pox, varicella zoster.
Most people who get shingles are over 60 years of age. The exact cause of the reactivation of the virus is not known. People who are under stress or have weakened immune systems seem to be especially vulnerable. The location of shingles on the body depends on the involved nerve. Most cases appear around the waist or on the upper chest or back.