If the patient’s nipple is downwardly inverted where it is empty, the causative cause can generally be categorized into primary (such as congenital ligament dysplasia) and secondary (such as breast cancer, etc.) 1. Primary: In the process of mammary gland development, some ligaments behind the nipple are not well developed, resulting in pulling on the nipple, so the nipple may also be inverted. If these ligaments are injured due to trauma, contracture may also occur during the repair process and the nipple may also be inverted. Patients can massage and lift the nipple to restore the inverted nipple. 2. Secondary: If the nipple used to be fine during development, but recently found that the nipple is inverted, there may be inflammation or serious diseases, such as breast cancer, etc., which leads to contracture of the ducts and ligaments, and pulls the nipple to cause nipple inversion. In this case, the patient must go to the hospital as soon as possible to clarify the cause of the disease and receive treatment as prescribed by the doctor. If you find that the nipple downward inversion is empty, it is recommended to go to the hospital as soon as possible, and follow the doctor’s instructions for treatment.