Anyone who has ever had chicken pox is at risk for developing shingles. Shortly after chicken pox heals, the virus moves from the skin to an area close to the spinal cord and brain. The virus remains there for many years undetected. It can become active when a person’s immune system is weakened.    There are some factors that might increase the risk of developing shingles: Age–The risk of developing shingles increases with age. Shingles is more common in people older than 50. Experts say that half of all people age older than 80 will develop shingles. Certain Diseases–Anything that weakens your immune system, such as HIV/AIDS and cancer, increases your risk for developing shingles. Cancer Treatments–Chemotherapy or radiation can weaken your immune system and may increase your risk of shingles. Medications–Drugs that are designed to prevent the rejection of transplanted organs can increase your risk of shingles. Any prolonged use of steroids can also trigger shingles.