Shingles is a painful rash caused by the varicella-zoster virus, which is the same virus that causes chickenpox. After a person recovers from chickenpox, the virus stays dormant (inactive) in the body. The virus can reactivate years later, causing shingles. The reason for reactivation is unclear, but it may be due to lowered immunity to infections as people get older. Shingles is more common in older adults and in people who have weakened immune systems. Other factors that can increase the risk of developing shingles include:

• Age: The risk of developing shingles increases with age. Shingles typically occurs in people older than 50, and people over the age of 60 are more likely to experience more-severe complications.

• Diseases that weaken the immune system, such as HIV/AIDS and cancer, can increase the risk of shingles.

• Cancer treatments: Radiation or chemotherapy can lower the bodys resistance to diseases and may trigger shingles.

• Neurological problems: Shingles may cause inflammation of the brain (encephalitis), facial paralysis, or problems with hearing or balance.

• Skin infections: If shingles blisters arent properly treated, they can become infected.

Its important to note that shingles is not contagious, but a person with shingles can spread the varicella-zoster virus to others who have never had chickenpox or the chickenpox vaccine. These people can get infected with the virus through direct contact with the fluid from shingles rash blisters or breathing in virus particles that come from the blisters. If they get infected, they will develop chickenpox, not shingles. They could then develop shingles later in life.