The reason why women’s breasts are swollen and painful before menstruation is: First, it may be that the ovarian secretion of estrogen and progesterone levels rise, which will stimulate the breast ducts and mammary vesicles, and there will be chest swelling and pain, which is a normal physiological phenomenon, so pay attention to wearing loose underwear and avoid scratching. Second, may be more irritable mood, the emergence of liver qi depression, will also lead to chest swelling pain. Third, when women suffer from breast diseases such as breast enlargement or breast nodules, there will also be chest swelling and pain. The physiological chest swelling and pain will be relieved and disappear after the onset of menstruation to keep the mood calm, if the chest swelling and pain is always present, you need to go to the hospital for ultrasound examination of the breast if necessary to give early diagnosis and treatment.