Postherpetic neuralgia (PHN) results from damage to nerve fibers during shingles infection. The nerve fibers at the skin in the affected area send exaggerated pain signals to your brain. Postherpetic neuralgia means nerve pain after herpes. Shingles is also called herpes zoster. Shingles is caused by the varicella-zoster virus, the virus that causes chickenpox. Once you’ve had chickenpox, the virus remains in your body for your entire life, but is dormant or “silent” for years. When the virus becomes reactivated, it causes shingles. A certain percentage of people (< 20%) who get shingles develop PHN.