With the increase in online science articles, there are many family members who are aware of the presence of circumcision and phimosis in their children. In the back of their minds, they know that they need to do the surgery to give their children happiness for the rest of their lives. However, many parents, including my own close friends, are asking me for advice on exactly how old their children should be before they have the surgery so that it is best for their physical development? Is it circumcision or phimosis? Before figuring this out, one truth that parents must know is that almost all children before the age of 3 have a problem with circumcision. It is only after the age of 3 that a child’s foreskin slowly begins to turn up. So, don’t think about the question of whether or not to operate before the age of 3. After the age of 3, when the child reaches school age, if the foreskin still covers the glans completely, it is called “phimosis” if the glans can be revealed by turning the hand up. If the glans cannot be revealed by turning it over with the hand, it is called “phimosis”. How old is the most appropriate age for circumcision? Whether it is “phimosis” or “circumcision”, the most appropriate age is different. After the age of 3, if the child is circumcised and the glans cannot be revealed even after trying to turn up the foreskin, surgery is recommended as soon as possible. Specifically, the age before 7 years of age is generally considered ideal, with fewer intraoperative and postoperative risks. After the age of 3, if the child is circumcised, the operation can be avoided without affecting the child’s future development if the child can be cleaned well every day. If the child can not be cleaned well, or even have circumcision, glans, it is also recommended to operate as early as possible. Specifically to the age, generally considered the most appropriate around 12 years old. At this time the child is already obedient and often the operation can be done under local anesthesia. Does general anesthesia affect the child’s intelligence? I know that the main reason that prevents parents from circumcising their children is the fear of the effect of anesthesia on the child’s intelligence. For this reason, I have consulted the head of the anesthesiology department to provide you with the relevant information. Based on the available medical evidence, both clinical studies and animal studies have shown that anesthesia for a single, relatively short procedure (less than 3 hours) has no effect on a child’s behavior or learning ability. As for our circumcision, even with general anesthesia, the maximum duration of the procedure is no more than one hour, and if it is fast, it is basically over in half an hour.