The normal length of the foreskin is about one centimeter, which means that under normal circumstances, the foreskin cannot cover the glans, but it can expose the glans. If the foreskin still covers the glans penis in an erect state, it is clinically called foreskin too long. If the penis head cannot be exposed in an erect state, it is clinically called phimosis. Normal foreskin length generally does not require surgery, and it is enough to keep the lower body clean and hygienic. For patients with phimosis, circumcision is recommended.