Shingles, also known as herpes zoster, is a painful rash caused by varicella-zoster virus (the same virus that causes chickenpox). After a person has had chickenpox, the virus continues to reside in the body, causing no symptoms. Later in life, it can become active again, causing the shingles rash. Shingles can affect people of all ages. It is particularly common in adults over age 50. It is also more common in people of all ages with conditions that weaken the immune system. The shingles rash first appears as a painful or tingling area on one side of the body and progresses to a rash of small blisters. There is now a shingles vaccination for people age 50 and older to help prevent shingles.