Shingles – MayoClinic.com

Shingles is a viral infection that causes a painful rash. It often appears as a band of blisters that wraps from the middle of your back around one side of your chest to your breastbone. Other parts of your body can be involved as well, including your neck, face or scalp.

The pain of shingles can be excruciating, and the cause might not be immediately evident. But once the telltale rash and blisters start on one side of your body, it's more easily identified as shingles.

Shingles is caused by the varicella-zoster virus, the same virus that causes chickenpox. After you've had chickenpox, the virus lies inactive (dormant) in your nerves. Years later, the virus may reactivate as shingles.

Shingles isn't a life-threatening condition, but it can be very painful. Sometimes, the rash leads to a debilitating complication called postherpetic neuralgia. This condition causes the skin to remain painful and sensitive to touch for months or even years after the rash clears up.