Mammography is used for breast cancer screening, and the results may be different when the test is done before and after menstruation, which is due to changes in hormone levels. Before menstruation, the human body’s progesterone level is higher, the breast ducts are in the state of hyperplasia, and the density of the breast is relatively high, which is easy to obscure small lesions, resulting in missed diagnosis, etc. Therefore, clinics often arrange patients to have the examination after menstruation, when the breast tissue is relatively loose, the edema of the breast ducts disappears, and the vision is clearer when the examination is carried out. If there is any breast discomfort, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor to carry out the appropriate breast examination, if there are abnormalities, the need for early treatment.