Reasons for chest pain before each menstrual period: 1. Physiological factors. Before and during the menstrual period, it is inevitably accompanied by fluctuations in the levels of estrogen and progesterone. Hormonal changes may cause changes in the blood circulation of breast tissue, leading to congestion and edema in the breast tissue and pain. During and before menstruation, women’s breasts, especially the nipples, may also become extra sensitive, and some minor stimuli may cause painful symptoms. The emotional changes before and after menstruation are also one of the main causes of breast pain. 2. pathological factors. Mammary gland hyperplasia is the most common disease that causes painful symptoms in the breast during menstruation and is closely related to the action of estrogen. Breast fibroid is a benign tumor disease that occurs in the breast tissue, and the main symptom is breast pain of varying degrees during and around the menstrual period.