A long prepuce is a common male disease. Before the age of 7, the foreskin is longer and can completely cover the glans penis and the external urethral orifice. With the development of puberty, the volume of the penis increases in size and length, and the foreskin retracts backwards. By adulthood, the glans penis becomes exposed. However, in about 30% of adults, the foreskin still completely covers the glans penis. Only when the foreskin is manually retracted or when the penis is fully erect and the glans penis and the urethral orifice are exposed, it is called a long prepuce. When the foreskin opening is too small and too tight to retract, and the glans penis and the urethral orifice cannot be exposed even during erection, it is called phimosis, which accounts for about 8%.