You can also get shingles after having chickenpox. Chickenpox and shingles are both caused by varicella-zoster virus infection. When the human body is first infected with varicella-zoster virus, chickenpox or latent infection can occur. Chickenpox is a self-limiting disease and will soon be cured with antiviral and symptomatic treatment. However, after chickenpox is cured, the virus is not cleared but is latent in the posterior spinal root ganglion. When the body is in a situation of fatigue, stress, mental trauma, or suffering from chronic diseases such as diabetes or tumor, which leads to a decrease in the body’s immunity, the virus can be reactivated, causing secondary infection and the occurrence of herpes zoster. Herpes zoster is also a self-limiting disease, and mild cases can be treated without medication. Elderly patients or those with severe pain should apply antiviral medication as early as possible to avoid leaving posterior neuralgia.