The causes of breast shrinkage may be related to congenital developmental abnormalities, physiological breast atrophy, breast cancer and other disease factors. 1. Congenital developmental abnormality: For some patients, the situation of breast shrinking inward cannot be ruled out due to congenital developmental abnormality, such as nipple inversion, if there are no other clinical symptoms, it can be temporarily observed, not dealt with, and do a good job of hygiene and care. 2. Physiological breast atrophy: the breast mainly contains mammary glands and fat components, in the case of excessive dieting, the body’s estrogen level drops rapidly, will cause women to physiological breast atrophy, timely dietary adjustments can be made, generally do not need special treatment. 3. Breast Cancer: Breast shrinkage to the inside is not excluded due to the factors of breast cancer, which is a malignant tumor, there will be breast dimple sign, cellulite changes and nipple inversion, etc., with the doctor to carry out examinations, and give surgery and radiotherapy and other treatments. Breast shrinkage inward also consider non-lactating mastitis and other causes, it is recommended that the patient can go to the breast surgery department of the hospital to clarify the specific causes of breast shrinkage inward, and then give targeted treatment and therapy.