Risk factors

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:

• Being older than 50. Shingles is most common in people older than 50. The risk increases with age.
• Having certain diseases. Diseases that weaken your immune system, such as HIV/AIDS and cancer, can increase your risk of shingles.
• Undergoing cancer treatments. Radiation or chemotherapy can lower your resistance to diseases and may trigger shingles.
• Taking certain medications. Drugs designed to prevent rejection of transplanted organs can increase your risk of shingles — as can prolonged use of steroids, such as prednisone.