Severe bilateral breast asymmetry is mostly caused by congenital factors, and in fact, it is a kind of congenital developmental malformation. During the embryonic development, if there is abnormal development in the mammary bud on one side, then during the breast development period, the two breasts will be obviously asymmetrical, with the underdeveloped side significantly smaller than the healthy side. Although this condition does not affect marriage or reproduction, it may cause feelings of inferiority. Therefore, after the healthy side of the breast has fully developed, you can consider choosing an appropriate time for breast augmentation surgery using implants, making the originally flat breast as full as the healthy side, restoring the charm and confidence of women.