Shingles, also known as herpes zoster, is a viral infection that causes a painful rash. It is caused by the varicella-zoster virus, the same virus that causes chickenpox. After a person has had chickenpox, the virus lies dormant in nerve tissue near the spinal cord and brain. Years later, it can reactivate as shingles. Understanding the early signs and duration of the shingles rash can help in managing the symptoms and seeking timely treatment.