Precocious puberty refers to the early onset of puberty, i.e., the appearance of enlarged gonads and secondary sexual characteristics, i.e., breast development, appearance of pubic and axillary hair, rapid growth in height and weight, development of external genitalia, or the appearance of menstruation before the age of 10, and testicular enlargement before the age of 9 in males. According to the pathogenesis, precocious puberty can generally be divided into two major categories: gonadotropin-releasing hormone (GnRH)-dependent precocious puberty (true precocious puberty) and non-GnRH-dependent precocious puberty (pseudo-precocious puberty); the former is called central precocious puberty or complete precocious puberty, and the latter is called peripheral precocious puberty. In addition, incomplete precocious puberty, such as simple premature breast development and simple premature pubic hair, has been classified as a variant type of pubertal development. Since sexual development is related to a variety of factors and human growth and development is a continuous process, there is no very precise boundary, so a comprehensive examination is needed. Precocious puberty is more common in girls, and the incidence of idiopathic precocious puberty is about 9 times higher in girls than in boys, while precocious puberty in boys is characterized by a higher incidence of central nervous system abnormalities (e.g., tumors), and central precocious puberty is clinically characterized by the early development of sexual characteristics, which is similar to the normal pubertal developmental program, but the clinical manifestations vary widely and can develop in all age groups before puberty, with symptoms developing at different rates, some of which can be seen in sexual Some of the symptoms may develop after a certain degree of sexual development and then pause for a period of time, while others may develop again after the symptoms have subsided. During the process of sexual development, both boys and girls show rapid growth in height and weight and accelerated skeletal maturation, and due to the rapid growth of bones, the epiphysis may fuse earlier, and although the height of the early stage is higher than that of children of the same age, the height of the adult is shorter. After puberty, all children are normal except for their height, which is shorter than the general group. The sexual development process of peripheral precocious puberty is very different from the above-mentioned pattern. In boys with precocious puberty, the size of the testes should be noted. If the testes are >3ml, it suggests central precocious puberty, while if the testes are not enlarged, but masculinity develops progressively, it suggests peripheral precocious puberty, whose androgens may come from the adrenal glands. In cases due to intracranial tumors, only precocious puberty may be manifested early in the course of the disease, and only later do localized signs such as increased intracranial pressure and visual field defects appear, which need to be alerted.