After menstruation, the patient’s estrogen is still within the high range, and at this time the breast gland, alveoli and ducts are in a state of breast hyperplasia, so the patient will still have a feeling of breast swelling after menstruation clears, which is a common clinical condition of physiological breast hyperplasia. The cause of this hyperplasia is due to the stimulating effect of estrogen in the breast, and the protection of progesterone has not yet been fully developed. Often the patient’s symptoms gradually resolve after menstruation clears. Local thickening of the breast glands can be palpated and even some patients have irritating pain. This condition often does not require special treatment, and the symptoms will gradually resolve some time after the end of the menstrual cycle, and the symptoms are cyclical in nature. Of course, in some patients, after menstruation, in addition to some swelling and nodules can be palpated, and the nodules gradually increase in size, it is recommended that patients should have surgery to remove the nodules, because after all, a small percentage of mammary hyperplasia will progress to breast cancer.