Breasts appear left and right sides are not equal, the size of the situation is not the same, in the clinic is generally due to the following reasons: a situation may be due to the movement habits of the people concerned, the size of the breasts is generally related to the posture of the movement, the amount of movement is closely related to, for example, the common right hand of the right hand of the people who are often in the process of using the process of the right side of the pectoral muscles are more developed, it feels or can be seen from the surface relatively The right side of the mammary glands developed a little larger, the left side is relatively small. Another situation may be due to congenital factors, in the process of embryonic development, one side of the mammary glands developed abnormally, after birth there will be bilateral mammary glands are not equal, the size of the situation is not the same. In addition, some breastfeeding women due to breastfeeding causes asymmetry is also more common, mostly due to the habit of breastfeeding on one side of the breast more, the other side of the relatively less, so after breastfeeding and weaning, the frequent breastfeeding side of the breast atrophy, the emergence of the size of the case of unequal, but this situation does not have any effect on the woman.