Boys and girls in adolescence before the height growth of about 5 cm per year, after entering puberty, children’s growth rate will enter a sudden jump in the period there are great changes. Girls grow faster when their breasts begin to develop, the fastest growth in height is about a year after breast development, the average time from the beginning of breast development to full maturity is 3 years, usually the fastest age of height growth for girls is at 11 to 13 years old, the fastest year of height growth can be 7 to 9 cm, the average increase in height in 3 years is 20. menstruation usually occurs after 18 months of rapid growth, the average age is The first menstruation occurs before the age of 12 years in 10% of girls and after the age of 15 years in 10% of girls, with the average onset of menstruation being approximately 2 years after the onset of puberty. When menstruation occurs, the rapid growth period is over and the growth rate begins to decline, signaling that children are nearing the completion of growth. In boys, rapid growth begins when the testes reach 10 mL in size, and the onset of puberty is usually considered to be when the testes increase to 4 mL, followed by the appearance of other secondary sexual characteristics such as pubic and axillary hair. The height surge occurs later in the development of genital and pubic hair, with beard and body hair appearing later in puberty. The average age of onset of pubertal growth in boys is 12.5 years, and the average age of fastest growth is about 14 years, with a total growth of 28 cm. Usually the beard grows to the point where it needs to be shaved indicating that it has entered late pubertal development and is nearing its final height.