Physical growth can be divided into three stages: Infancy up to 3 years old (rapid growth period): the fastest growth rate in the first year after birth, can grow 25 cm, the second year can grow 10 cm. Childhood 3 years old – puberty (growth slowdown period): this period of growth is mainly regulated by growth hormone, growth of 5-7 cm per year. Puberty 11-17 years old for girls and 13-20 years old for boys (growth acceleration period): Due to the synergistic effect of growth hormone and sex hormones, the growth rate of male and female children enters puberty and accelerates again, but due to the involvement of sex hormones, bone maturation also accelerates while increasing height, leading to epiphyseal closure and stopping height growth. Boys can grow 25-28 cm in height throughout puberty. Girls can increase their height by about 25 cm.