Shingles is a painful skin rash. It is caused by the varicella zoster virus. Shingles usually appears in a band, a strip, or a small area on one side of the face or body. Shingles is most common in older adults and people who have weak immune systems because of stress, injury, certain medicines, or other reasons. Most people who get shingles will get better and will not get it again. But it is possible to get shingles more than once. Shingles occurs when the virus that causes chickenpox to start up again in your body. After you get better from chickenpox, the virus "sleeps" in your nerve roots. In some people, it stays dormant forever. In others, the virus "wakes up" when disease, stress, aging, or some medications weaken the immune system. It is not clear why this happens. But after the virus becomes active again, it can only cause shingles, not chickenpox. Usually, one can't catch shingles from someone else who has shingles. But there is a small chance that a person with a shingles rash can spread the virus to another person. If you have shingles, avoid close contact with people until after the rash blisters heal.