The development of the penis of boys is often neglected by parents, coupled with the lack of proper knowledge of physiological hygiene, some children with external genital diseases are not detected in time, timely treatment or did not receive the correct treatment. Therefore, parents should understand some general knowledge of physiological hygiene, pay attention to check the child’s “penis”, problems timely to the regular medical institutions for consultation and treatment. The foreskin is the skin that is wrapped around the body of the penis. The foreskin and the head of the penis adhesion, can not completely turn up and expose the head of the penis is called the foreskin, which is a normal phenomenon in early childhood, with the growth of age and the development of the penis, the foreskin can mostly retreat upward on its own. Although the foreskin will not lead to discomfort, but because the foreskin can not be turned up, the foreskin under the accumulation of a lot of foreskin scale, if you do not pay attention to personal hygiene can lead to infection of the foreskin and urethra, pain or with increased urination, more serious pain when urinating and the urethra appear purulent discharge. At this time, you can use 1/5000 of potassium permanganate solution local dip, and under the guidance of the doctor to take antibacterial, generally a few days to improve. If inflammation occurs repeatedly, you should go to the hospital and receive manual separation or surgery to prevent more serious complications. Some children with severe prepuce have pinhole-like narrowing of the outer foreskin, which can lead to slow, small urine flow and foreskin puffing up during urination, etc. If this is the case for a long time, it is not only easy to induce infection, but also affects the normal development of the urinary system, and even the formation of hydronephrosis, which should be treated early. The size of the penis is directly proportional to the age, and some obese children appear short because of the accumulation of fat in the lower abdomen, making the penis buried in it, but the penis body development is mostly normal. Only a very small number of children have an occult penis and need surgery. If the exposed penis body is still very short, the child should be taken to a specialist hospital. Pay attention to the cleaning of the vulva can reduce the occurrence of circumcision and urethritis, cleaning methods are as follows: let the child urinate before cleaning, parents wash their hands clean, one hand fixed the child’s penis, the other hand will turn the foreskin upward, fully reveal the front of the penis head, and then wash with flowing warm water, wash away the prepuce and residual urine traces. When washing, the action should be light, avoid using liquid and soap containing medicinal ingredients to avoid trauma, irritation and allergic reactions. After cleaning, gently dry with a soft towel, turn the foreskin back into position, and then wash the anus. When drying, wipe the penis first and then the anus, and finally change to clean underwear. The foreskin mouth is too tight or very small at birth, do not forcefully flip the foreskin. Otherwise, it will cause trauma or cause embedded prepuce.