Herpes zoster pain is mainly caused by the herpes zoster virus that damages the nerves, resulting in bioelectric leakage and stimulation of sensory nerves leading to pain. In clinical practice, we have found that many patients with a weak constitution tend to have severe pain. The length of time for the elimination of herpes zoster pain varies from as short as 10 days to as long as several decades, and I have seen elderly male patients with pain for 20 years.