Shingles is a viral infection that causes a painful rash. Although shingles can occur anywhere on your body, it most often appears as a band of blisters that wraps from the middle of your back around one side of your chest to your breastbone.
Shingles is caused by the varicella-zoster virus — the same virus that causes chickenpox. After you've had chickenpox, the virus lies inactive in nerve tissue near your spinal cord and brain. Years later, the virus may reactivate as shingles.
While it isn't a life-threatening condition, shingles can be very painful. Vaccines can help reduce the risk of shingles, while early treatment can help shorten a shingles infection and lessen the chance of complications.