Shingles is due to a reactivation of varicella zoster virus (VZV) within a person 's body. The disease chickenpox is caused by the initial infection with VZV. Once chickenpox has resolved, the virus may remain inactive in nerve cells. When it reactivates, it travels from the nerve body to the endings in the skin, producing blisters. Risk factors for reactivation include old age, poor immune function, and having had chickenpox before 18 months of age. How the virus remains in the body or subsequently re-activates is not well understood. Exposure to the virus in the blisters can cause chickenpox in someone who has not had it before, but will not trigger shingles. Diagnosis is typically based on a person 's signs and symptoms. Varicella zoster virus is not the same as herpes simplex virus; however, they belong to the same family of viruses.
where does the shingles virus hide in the body
nerve cells