If you’ve ever had chickenpox—and a staggering 99% of people born before 1980 have—you’re at risk for developing shingles later in life. But why is that, exactly?
The answer lies in the varicella-zoster virus (VZV), which causes chickenpox. Once you recover from chickenpox, the virus stays in your system permanently and can reactivate as shingles—a painful, blister-like rash—years later. Although chickenpox and shingles are caused by the same virus, they are not the same illness.
