The nipple is naturally sunken and is considered to be a symptom of nipple entropion, which is due to the poor development of the smooth muscle around the nipple, causing the nipple to pull inward. As the nipple is locally invaginated, it is easy to form inflammation in the nipple as well as in the ducts of the breast, which is prone to recurrent circulation over time, which is also considered to be the cause of dehiscence, and the nipple invagination affects normal breastfeeding. Generally, you can first use manual pulling or negative pressure suction treatment. During adolescent breast development, frequent nipple traction or negative pressure suction can make the nipple protrude, lengthen the milk ducts and fiber muscles, and make the nipple naturally convex to achieve the purpose of natural treatment. If the above methods still do not solve the problem, surgical treatment is generally chosen, and stent support can be used to correct nipple invagination. Regardless of which method is used, it is recommended to visit a regular hospital first, so that the doctor can examine and then guide the corrective treatment.