1.What is precocious puberty? The development of secondary sexual characteristics (such as breast enlargement, pigmentation of labia majora and minora, appearance of pubic hair, and menstruation) in girls before the age of 8 is called female precocious puberty. Boys with secondary sexual characteristics (such as testicular enlargement, penis growth and thickening, pubic hair, beard and throat knot) before the age of 9 are called male precocious puberty. 2.Why should we check and treat precocious puberty? (Hazards of precocious puberty) (1) Some precocious puberty is caused by tumors, such as ovarian, adrenal, intracranial tumors, etc., which must be examined to exclude. (2) Short stature: The height of children with precocious puberty may increase rapidly for a period of time at the beginning, but the growth of height will soon be inhibited, and the final height will be significantly shorter than that of normal children of the same age. The early stage often shows accelerated bone age, so it is necessary to do bone age film examination. (3) Psychological hazards: Children with precocious puberty do not have early sexual psychology, so they are vulnerable to confusion and harm because of the contrast with precocious sexuality. 3.What kind of precocious puberty needs treatment? Not every type of precocious puberty needs immediate medication. Clinically, after a series of examinations (such as bone age film, ultrasound of uterus, ovaries and adrenal glands, blood sex hormone level, Dabigia test, cranial MR, etc.), if the diagnosis is central idiopathic precocious puberty with prematurity of bone age and prediction of eventual adult height shortening, only then should sex hormone suppressant medication be given (such as Daphylline, Dabigia, Inhibiton, etc.). For other types of precocious puberty, we can observe the development of the disease on an outpatient basis or treat it according to the original disease (e.g., precocious puberty caused by adrenal tumors should be treated according to the treatment method of adrenal tumors). 4.What kind of medicine is used for treatment? What is the effect of treatment? What are the side effects of different drugs? What should I pay attention to during treatment? Central idiopathic precocious puberty with prematurity of bone age and prediction of eventual adult short stature is treated with GnRHa drugs, such as Dafylline, Dabigat, Inhibiton, etc., generally 60-100μg/kg/time, about once every 4 weeks, and the duration of medication can be 1 to 3 years, depending on the age of onset of the child and the situation after medication. Vaginal bleeding may occur briefly within 1-2 weeks after the drug is administered, but in general, the premature growth of the child will be suppressed and the height growth will be slowed down after 3-6 months of the drug. It is important to review the bone age film and height after medication, and also to monitor the sex hormone levels (LH, FSH, E2, T) regularly. 5. Q: I have a 9-year-old girl with breast development, is it precocious? Do I need to treat it? A: It is not precocious puberty, but pubertal development. Whether treatment is needed depends on the degree and speed of development, bone age and sex hormone level of the child. If the child’s bone age is normal and the development speed is not fast, no treatment is needed, but outpatient observation is required; if the bone age is advanced and the development is rapid (pubic hair appears in a short period of time, breasts are large B4-5, menstruation is present), puberty is accelerated, and intervention treatment can be considered if the predicted adult height is significantly lower than the genetic height. 6.What is the development of a normal girl? A: Normal girls start breast development at the age of 10 to 12, menarche occurs after 1.5 to 3 years, height growth stops after 2 to 3 years of menstruation, and height growth from menarche to growth stop is about 5 to 10 cm.