Nipple inversion in girls is usually related to congenital developmental defects, traumatic factors and nipple infection. 1. Congenital developmental defects: mainly related to genetic hereditary factors, the muscles of the nipple and areola are underdeveloped during the developmental period, which will result in the breast tissues not being able to support properly, thus causing nipple inversion. Nipple incision is feasible, which can effectively correct the symptoms of nipple inversion, and is recommended to be performed in adulthood. 2. Traumatic factors: For example, having had trauma or gravity impact may cause nipple inversion. As an adult, the nipple can be lifted by doing traction therapy. 3. Nipple infection: If the surface of the nipple has broken skin or skin lesions, it is easy to be infected when the local cleaning and care is not done properly, and it will cause nipple inversion when it forms scars. You should pay attention to nipple hygiene, and insist on washing with warm water, and then apply erythromycin ointment. Girls’ nipple inversion should also consider other causes such as chest wall diseases, and should be observed more often. If the problem still cannot be relieved after that, it is necessary to consult a doctor in time to analyze the cause and then treat the symptoms.