Smaller breasts may be due to breast atrophy, a relatively rare pathological breast lesion that usually occurs when the breasts become smaller unilaterally, but not together, due to inflammation of the tissues inside the breasts or a decrease in blood supply. In addition, it can also be a physiological breast reduction, which is due to a certain age, especially after the age of 50, women’s body hormone withdrawal after a lesion equivalent to a decline in hormone levels, and then the breast began to appear volume reduction, flaccidity, resulting in smaller breasts, this physiological lesion is two breasts together, so if the breast reduction is two together is normal. If the breasts become smaller unilaterally and there is an abnormal feeling, then we should consider if there is breast atrophy.