There is no clear relationship between breast enlargement and breastfeeding, and there is no such thing as breast enlargement decreasing after breastfeeding. Breast hyperplasia occurs when estrogen levels change during a woman’s menstrual cycle. The breast, as a target organ, will undergo proliferation and regeneration of breast cells when estrogen levels change and act on the breast periodically. If there is excessive hyperplasia and incomplete regeneration during this process, breast hyperplasia will occur, which is manifested by cyclic breast pain and hard lumps in the breast. If the pain is not very obvious, the duration of pain in one menstrual cycle is less than or equal to one week, and it does not affect your life and work. This kind of breast hyperplasia can be reviewed as long as it is done regularly, every six months with a mammogram. So there is no clear relationship with breastfeeding.