Nipple pain before menstruation can be caused by trauma, changes in hormone levels or mastitis. 1. Trauma: When the nipple area is hit by the outside world before menstruation, it can lead to damage to the soft tissue and cause nipple pain. 2. Hormonal changes: Before a woman’s menstrual period, her hormone levels will change significantly, which will cause stimulation of the breasts can also cause nipple pain, which is a common physiological phenomenon, generally do not need to worry too much. 3. Mastitis: Mastitis can be induced by bacterial infection of the breast area. In this case, nipple pain can also occur before a woman’s period. Nipple pain before menstruation can also be caused by diseases such as breast hyperplasia or breast cancer, and patients should go to the hospital in time.