Outside the head of the penis in men, there is a double layer of folded penile skin, which is the foreskin. When the foreskin is turned over, a ring-shaped narrowing behind the glans is called the coronal sulcus. There are many sebaceous glands in the skin near the coronal sulcus, which can produce a special smelling secretion in the form of white mud, called “foreskin scale”. The male foreskin, especially in childhood, is long, covering the entire head of the penis and the urethral opening. As the penis grows in size and length, the foreskin recedes backward, exposing the head of the penis and urethra outside the foreskin. If in adulthood, the foreskin mouth is narrow, or the foreskin and the head of the penis are still attached, the foreskin cannot be turned up to reveal the urethral opening or the head of the penis, which is medically called prepuce; if the foreskin can be turned up to reveal the glans, but the penis is in a weak state, the foreskin wraps all or most of the glans, it is called circumcision. When the foreskin is too long and circumcised, foreskin scale is easy to accumulate in the foreskin cavity, due to the moist and warm environment of the foreskin cavity, bacteria are more likely to breed here. If it is not washed frequently, it will be more suitable for bacterial reproduction and can cause recurrent episodes of circumcision (local infection) and chronic irritation to the penis head, which can lead to the occurrence of penile cancer. However, although circumcision and phimosis can cause penile cancer, you do not need to worry too much because the incidence of penile cancer is extremely low. Circumcision and phimosis can hinder urination and may lead to urinary tract infection. If there is narrowing of the external urethra at the same time, you may have difficulty in urination or even cannot urinate. When the foreskin is too long, the moist environment inside the foreskin cavity is prone to infection with pathogens of sexually transmitted diseases such as condyloma acuminata, HIV, syphilis, soft chancre, genital herpes, etc. It may also be related to the fact that the mucous membrane of the inner plate of the foreskin that is too long is fragile and easily damaged during sexual intercourse. It was found that keratin is a barrier against HIV-1 virus infection. The lack of keratin in the inner foreskin plate and foreskin ties makes it easy to become an invasion site for HIV-1 virus and is the main gateway to HIV-1 virus infection in the penile area. After circumcision, the excessively long inner plate of the foreskin is removed, and the skin covering the penile body during erection is mainly the outer plate rich in keratin layer, which reduces the chance of HIV-1 virus infection. Theoretically, it is believed that when the foreskin is long and circumcised, the sexually sensitive areas such as the penis head, coronal groove and foreskin ties are not exposed or less exposed and less stimulated, so they will be more sensitive to sexual stimulation and will easily lead to premature ejaculation. However, there is no sufficient evidence to show that circumcised or circumcised people are more prone to premature ejaculation. As for some media claims that circumcision and circumcision can cause infertility, they are nonsense. It is important to note that people with long foreskin or prepuce should keep their sexual organs well lubricated during intercourse and should not move vigorously during intercourse to avoid embedded prepuce or torn ties. In case it occurs, you need to go to the hospital to deal with it, do not adjust to it lightly.