Male circumcision may lead to incarceration of foreskin, prepuce and glansitis, penile cancer, gynecological diseases and so on. 1. Foreskin incarceration: If the foreskin is too long, the glans cannot be exposed, and too much force is exerted when the foreskin is turned up, it may lead to foreskin incarceration, which is easy to cause pain, swelling and other symptoms. 2. Foreskin and glansitis: If the foreskin is not cleaned for a long time, it is easy to form foreskin scale, which will breed bacteria and fungal infection and induce foreskin and glansitis, leading to glans itching and pain, and when it is serious, it will also induce prostatitis, urethritis and other diseases, and due to the inflammatory material stimulation of glans area, it may also induce premature ejaculation. 3. Penile cancer: prolonged presence of circumcision, repeatedly induced prepuce and glansitis, and cancer may occur, inducing penile cancer. 4. Gynecological diseases: men who do not clean the inside of the foreskin for a long time may induce glans phimosis, which may cause the pathogenic bacteria to be transmitted to women during sex, and may easily induce gynecological diseases, such as vaginitis. Men who are circumcised should clean the inside of their foreskin frequently, and when recurrently induced glans phimosis, they may consider seeking surgical treatment.