There are many reasons for nipple inversion in female infants, the specific reasons are as follows: 1, congenital developmental defects, genes determine individual differences, the nipple and areola muscles are underdeveloped resulting in a lack of tissue support under the nipple resulting in nipple inversion.2, trauma or surgery, the girl has suffered a trauma or has undergone surgery resulting in nipple inversion.3, nipple infection to form a scar, resulting in nipple inversion.4, mammary tumors resulting in nipple retraction. . For congenital nipple inversion you can take manipulation pulling, 30 minutes a day, 2-3 times a day, or take a breast pump to suck out, adhere to 2-3 months can be. If the first two kinds of ineffective to take surgery to loosen the shortened ligament, if the nipple inversion caused by mammary tumor, need to determine the benign and malignant nature of the tumor, if it is malignant should be removed from the breast, and actively carry out chemotherapy in the postoperative period.