Anyone who has ever had chickenpox can develop shingles. Most adults in the United States had chickenpox when they were children, before the advent of the routine childhood vaccination that now protects against chickenpox.

Factors that may increase your risk of developing shingles include:

  • Age. Shingles is most common in people older than 50. The risk increases with age. Some experts estimate that half the people who live to the age of 85 will experience shingles at some point in their lives.
  • Diseases. Diseases that weaken your immune system, such as HIV/AIDS and cancer, can increase your risk of shingles.
  • Cancer treatments. Undergoing radiation or chemotherapy can lower your resistance to diseases and may trigger shingles.
  • Medications. Drugs designed to prevent rejection of transplanted organs can increase your risk of shingles — as can prolonged use of steroids, such as prednisone.
Sep. 01, 2011