Breast development in girls at the age of 8 may be precocious, precocious refers to early sexual maturity, which may make the girl’s epiphysis close early leading to short height. Girls generally start breast development at the age of 8-13. If breast development, pubic hair growth and menstruation start before the age of 8, it is most likely precocious; while breast development after the age of 8, but no other manifestations and normal growth and development, it may be a normal situation and there is no need to worry. In addition, if a girl’s recent weight gain is too fast, it can also cause the accumulation of fat in the chest, resulting in the appearance of breast enlargement, but if there is no breast development, it is not precocious. Therefore, parents should pay attention to identify the above situations. The common triggering factors that cause precocious puberty are the following: 1. Diet: consuming too much fried food such as fried chicken and French fries may cause excess heat to accumulate in the body to form excess fat, affecting hormone secretion and leading to precocious puberty. Poultry in the market may use ripening agents to promote the growth of poultry, and excessive consumption of poultry meat may also lead to excessive intake of growth hormone-like substances leading to sexual maturity, so attention should be paid to improving the dietary structure; 2, work and rest: long-term sleep instability may affect the secretion of hormones in the body, which may lead to precocious maturity; 3, disease: some girls are born with abnormal development, or suffer from diseases that cause the pituitary gland to secrete excessively. If girls use hormone-containing cosmetics too early, it may lead to premature development of the pituitary gonads in the hypothalamus due to stimulation, thus leading to premature maturity. In addition, precocious puberty is divided into true precocious puberty and pseudo-precocious puberty, so if parents suspect that girls have symptoms of precocious puberty, they should go to the hospital for relevant examinations in time to identify the causes and decide whether symptomatic treatment is needed according to the specific situation.