A reactivation of the chickenpox virus in the body, causing a painful rash. Shingles may also be referred to as herpes zoster. What is shingles? Medically reviewed by Stacy Sampson, D. What is shingles? What does shingles look like? Readers Comments 100 · Share Your Story. What causes shingles? Shingles, or herpes zoster, is a painful skin condition that results from a reactivation of an infection with the varicella zoster virus, the same.