8 weeks old daughter of one side of the breast has a hard lump, the principle of consideration is breast development, is a sexual development in advance, the age of normal sexual development of girls is 11 years old, between 8-11 years old breast development, the clinical diagnosis of sexual development in advance, if earlier than the age of 8 years of age sexual development in advance, the diagnosis of precocious puberty, the situation needs to take the child to the hospital, bone age and gonadal ultrasound examination. Early sexual development of girls will have the following three main effects: First, it will affect the child’s height, which will lead to the child’s lifelong height in adulthood is too short. Second, it will lead to early menstruation. Third, due to early sexual development, it will lead to some psychological changes in children, and there will be some psychological behavioral abnormalities, so when the sexual development is abnormal, you need to go to the hospital for a detailed examination, to clarify whether it affects the child, and under the guidance of the doctor to give reasonable intervention.