It is not normal for a 7-year-old girl’s nipple to grow out. Under normal circumstances, the nipple should be exposed on the surface of the breast, which may be related to congenital nipple deletion, nipple inversion and other conditions. 1. Congenital absence of nipple: This is a rare case, and the typical symptom is that there is no nipple on the chest of the girl after birth, which belongs to congenital developmental abnormality. Some patients may be accompanied by the phenomenon of missing nipple on one side of the breast, or both breasts may be missing. 2. Nipple inversion: Considering the phenomenon of nipple inversion in female babies, it is manifested as the nipple is partially sunken into the breast, and only half of the nipple can be seen on the outside. It is also possible that the nipple has completely disappeared and the whole nipple has been sunk into the breast tissue, with only a small hole in the female breast. Parents are advised to bring their children to the clinic in time for a systematic examination to clarify the cause of the disease.