Most women experience cyclical breast pain with their menstrual cycle. This is because as the menstrual cycle changes, there are fluctuations in the level of estrogen produced by a woman’s ovaries, and when estrogen levels are high, the mammary glands can become hyperplastic. In the process of breast hyperplasia, the glandular cells inside the breast gland will be enlarged and the ducts can be dilated. At this time, because of the overall swelling of the breast gland, it may compress or stimulate the nerves, which will cause some pain. However, most of the pain is actually not very serious, or even a swelling sensation when it is mild. If there is more swelling and it is more noticeable, then pain will occur. The severity of the pain is related to menstruation, but the pain is not the same every time you menstruate, and the duration of the menstrual flow can vary every time you menstruate, as long as it is within the normal range, it is acceptable.