Seven-year-old girls with hard and painful breast nuclei may be precocious puberty, if there are other symptoms or caused by organic lesions of the central system or hypothyroidism and other diseases, need to be properly treated under the guidance of a doctor. Precocious puberty is divided into partial precocious puberty and true precocious puberty. Partial precocious puberty refers to simple breast development, seven-year-old girl breast nucleus has a hard lump pain if the examination is diagnosed as partial precocious puberty, generally do not need special treatment, remind the child to pay attention to daily not to eat puffed food, do not drink drinks, eat more fresh vegetables and fruits. If the examination for true precocious puberty, need to give different treatments according to different causes. For example, if the disease is caused by central organic lesions, necessary treatment such as tumor removal and hydrocephalus drainage can be given. If caused by hypothyroidism, thyroid preparations such as levothyroxine sodium tablets can be used as prescribed by the doctor to correct thyroid function. Parents are advised to bring their children to the hospital in time for clear diagnosis and treatment. In addition, parents must pay attention to the child’s psychological changes in time, and actively help the child to relieve the bad mood.