Breast swelling and pain a few days before menstruation may be caused by changes in hormone levels in the body, breast hyperplasia and other factors, it is recommended that the patient go to the hospital in a timely manner to do the relevant examinations, a clear diagnosis, and give appropriate treatment. 1. Changes in hormone levels in the body: generally due to increased levels of estrogen and progesterone in the female body, which stimulates the breasts, and is prone to breast engorgement, resulting in breast swelling and pain, which is a normal physiological phenomenon and does not require any special treatment, and the symptoms will disappear after the onset of menstruation. 2. Breast hyperplasia: due to endocrine disorders during the menstrual cycle, and after the onset of menstruation, the symptoms are not relieved, it may be the case that breast hyperplasia leads to pain in the patient’s breasts, accompanied by symptoms such as breast lumps. In addition, it is recommended that patients should pay attention to maintain an optimistic mood, try to avoid excessive fluctuations in mood, and avoid spicy, cold and other stimulating foods in the diet.