Breast enlargement is generally common in young and middle-aged women, with the most common age group being between 25 and 45 years old. Breast hyperplasia is a condition in which the breast, as a target organ for estrogen, periodically undergoes proliferation and regeneration of breast cells as estrogen levels change during the menstrual cycle. Breast hyperplasia occurs if there is excessive proliferation of breast cells and incomplete regeneration during this process. The most important clinical manifestations of breast hyperplasia are cyclic breast pain and breast lumps. Cyclic pain is related to the menstrual cycle, and breast lumps are not the same as breast tumor lumps. Therefore, the pain of breast hyperplasia is not very serious and does not affect your work and life, as long as you have regular checkups, usually every six months to review the breast ultrasound.