People who have had chickenpox and are over the age of 50 or who have weakened immune systems are at the greatest risk of developing shingles, states WebMD. Others at risk include people who have experienced trauma or people who live stressful lives.
People who have cancer or people who are undergoing treatment for cancer are also at a greater risk of developing shingles, according to WebMD; however, a person must have already contracted chickenpox to get shingles. The virus that causes chickenpox remains dormant inside the body long after symptoms of the disease have gone away. In some people, this virus becomes active and travels down the nerve fibers into the skin causing the painful rash associated with shingles.