1. Precocious puberty of intracranial origin Premature development or function of the reproductive tract due to hypothalamic or pituitary lesions, except for premature maturation of ovarian follicles and ovulation, is the same as that seen in normal children. About 80-90% of somatic precocious puberty has no obvious cause. It is often classified as precocious puberty of central nervous origin by etiology, because the patient may have small but unproven hypothalamic lesions. Some patients have a family history of precocious puberty. 3, precocious puberty due to ovarian tumors Ovarian tumors deserve to be emphasized as a cause of precocious puberty, but feminizing tumors are actually common in childhood. 4, other causes of precocious puberty Hormone-producing adrenal tumors can cause heterosexual or mixed type precocious puberty. Exogenous estrogens are mostly due to improper medication or other sources. Young girls who mistakenly take their mothers’ contraceptive pills can occasionally cause precocious puberty; children with hypothyroidism can occasionally have precocious puberty. 5. Temporary precocious puberty is rare, but not uncommon. Children often have accelerated development of one or more secondary sexual characteristics. Most of these children show body growth and breast development (about 50%). Vaginal bleeding is present in up to 45% of cases. This kind of premature sexual development lasts for a few months and can return to normal development and later enter normal puberty at a normal age.