Precocious puberty in children is a common pediatric endocrine disorder in which children exhibit sexual characteristics that do not correspond to their actual age. It mainly refers to the appearance of secondary sexual characteristics in boys before the age of 9 and in girls before the age of 8 or the onset of menstruation before the age of 10. The specific clinical manifestations of precocious puberty in children are as follows: 1. Children of either sex: the common manifestation of precocious puberty is linear acceleration of height growth and accelerated bone maturation, but the final height will be lower than normal. If there are intracranial tumors and other central nervous system lesions, headache, nausea, vomiting, vision changes or other neurological symptoms may occur. 2. Secondary sexual characteristics of boys: testicles and penis enlargement, testicular volume greater than 4ml, need to suspect the emergence of precocious sexual maturity. There may be pubic hair, black hair in the armpits, throat knots, thickening of the voice, low voice, muscles become developed, shoulders will widen and appear more robust. 3. Special manifestations of girls: (1) Breast development: often the first to appear is the simultaneous enlargement and bulging of both breasts, which are painful when touched with hard knots; (2) Labia minora becomes larger or pubic hair appears: thickening of labia minora and vaginal mucosa, visible pigmentation, coloring of labia majora, long black hair in the armpits, and light black pubic hair sprouting from the pubic area; (3) Vaginal bleeding or discharge: at first it is mostly irregular vaginal (4) Widening of the pelvis may appear: the subcutaneous fat increases, and the curves of a young girl will gradually become obvious, etc. Precocious puberty in children is harmful and affects the growth and development of the child. If precocious puberty is found, you should seek medical attention in a timely manner at a hospital to conduct a bone age test to predict future height, as well as check the volume of testicles in boys, and the size of ovaries and uterus in girls through ultrasound, and the thickness of the endometrium of the uterus.