The so-called prepuce is the foreskin covering the urethral opening, in general, babies under the age of three are not diagnosed with prepuce. Both prepuce and foreskin (foreskin still cannot be turned up in boys aged 2 to – 3 years old) can cause inflammation of the head of the penis. If the inflammation spreads upward, it can cause urinary tract infection; repeated episodes can cause adhesion of the foreskin or head of the penis, leading to narrowing of the urethra or front urethra; the foreskin cannot be turned up without the opportunity to wash, so that the dirt in the foreskin remains for a long time, which causes difficulty in urination or prolonged urination; if the forced upturn is very easy to cause can not be reset, the foreskin embedded in the coronal groove of the penis, forming a narrow ring, called embedded prepuce. The blood circulation of the embedded penis is obstructed, so the penis head and foreskin are prone to infection and ulceration or even necrosis; the recurrence of prepuce penile head infection and the chronic stimulation of foreskin scale can contribute to the occurrence of penile cancer; the untreated prepuce and foreskin will affect sexual desire and fertility in adults. The circumcision refers to the narrow opening of the foreskin and the difficulty of turning up the foreskin. To determine whether it is circumcision or prepuce, you can determine through self-examination by applying soap to the penis, lubricating the foreskin inside and outside, fixing the penis with the left hand, pushing the foreskin backward with the right hand and turning it over, if the foreskin can be turned up smoothly, it is circumcised; if the foreskin mouth is too small to be turned up, it is circumcised. Most of the circumcision is congenital. Some of them are caused by repeated infections on the basis of circumcision, resulting in adhesions that cannot be turned up. Circumcision is much more harmful to a person’s body than circumcision. In some severe cases, the foreskin opening is as narrow as a pinhole, and the foreskin bulges like a ball when urinating, making urination difficult. Due to the circumcision and narrow urethral opening, the bladder sphincter contracts during urination, and the internal pressure of the bladder exceeds the pressure that the bladder’s hairy sheath can withstand before or while overcoming urethral resistance, and urine refluxes along the ureter, and the ureter and renal pelvis expand, causing upper urinary tract bacterial infections and scar formation, and leading to secondary reflux nephropathy and even renal function damage.