If your breasts do not appear the same, don't worry. Many people have breast asymmetries. One breast may be bigger or smaller, sit higher or lower on the chest, or be of a different shape. Breast asymmetries can result from developmental differences, post pregnancy and/or breast feeding, previous surgery or traumatic injuries. Although we are not mirror images of ourselves, the appearance of breast asymmetries can be improved by using different size or shaped implants, or performing a mastopexy (breast lift) on one breast.