Herpes Zoster, commonly known as shingles, is a viral infection caused by the reactivation of the varicella-zoster virus, which also causes chickenpox. After a person recovers from chickenpox, the virus remains dormant in the nervous system and can reactivate later in life, leading to shingles. Symptoms typically include a painful rash, blisters, and itching, usually appearing on one side of the body. The condition is more common in older adults and individuals with weakened immune systems. While shingles can be painful, vaccines are available to help reduce the risk of developing the infection and its complications, such as postherpetic neuralgia, which can cause long-lasting pain.