A few days before menstruation, breast swelling is a normal physiological phenomenon, mostly due to the increase in progesterone during this period, progesterone will promote the growth of breast follicles, so the whole breast will be enlarged, the woman will feel the situation of breast swelling. Therefore, women should pay attention to proper rest during this period, keep the breasts clean and hygienic, avoid being bumped and squeezed, and also maintain a stable mood to avoid irritability. After menstruation, the level of progesterone decreases, breast swelling and pain will be relieved, women in the breast swelling and pain, but also pay attention to observe the breast whether there is a nodule or nipple overflow situation exists, the existence of these unexpected circumstances may be the occurrence of breast disease, need to be given under the guidance of the doctor to deal with the symptoms, so as to avoid delay in the treatment of the disease.