The physical development of a boy goes through three stages: the hazy stage, puberty, and maturity. Through these three stages, a boy will change from a boy to a man.

Generally, the physical development of boys is later than that of girls, and before the age of 11, they are in the hazy stage, where the development of their reproductive organs is in a state of stagnation. At this time, boys are about the same height, weight and endurance as girls of the same age.

11~18 years old is the puberty of the boy, at this time the boy's secondary sexual characteristics began to develop. 18~25 years old is the youth period, or called the late puberty. In a broader sense, both puberty and late adolescence can be called adolescence.

At this time, a boy's testicles enlarge significantly and begin to secrete androgens. Under its action, the boy's body undergoes a series of changes: the appearance of a laryngeal knot, the growth of armpit hair and beard, the beginning of voice change, the height soared, while the scrotum, penis enlargement, the growth of pubic hair, seminal emission and so on.

Generally by the age of 22 or so, the boy's pubertal development is basically complete, physically become a grown man. Thereafter, the boy enters the mature stage of physical development, bone closure, growth gradually stop. Boys' physical development is related to their living environment and genetic factors, but individual differences are not too great and basically follow the above pattern. If there are any abnormalities, such as "precocious puberty" or "late puberty", you should consult a doctor.

Boys also experience a lot of psychological changes during puberty. They are puzzled by the shape of their bodies and the physiological changes they experience, and are eager to find out what's going on. They are also nervous and fearful of abnormalities in their bodies, but they don't dare to tell their mothers about them.

At this time, if the boy from classmates, movie and television works, pornographic books and other channels to understand a half-understanding of the relevant information, often get distorted knowledge of sex, which will make the boy can not get timely and correct guidance, will affect the boy's physical and mental health and development of the consequences of the evil.

Understanding the trilogy of boy's physical development and making the boy go through puberty easily and safely is the responsibility and obligation of the mother.