Breast disease has its own specificity and the timing of the examination is related to the menstrual cycle. During different periods of the menstrual cycle, the breast gland undergoes some physiological changes of proliferation and rejuvenation due to the influence of various related endocrine hormones. In the premenstrual period, the estrogen level is higher, the proliferation of breast gland tissue will be more obvious, the breast tissue will be congested and edematous to different degrees, the whole breast will be thicker, and the relevant examination will not be so suitable, which will affect the judgment of the nature of breast lumps. If you need to take an f-target X-ray of the breast, it will be more painful to clip it. Therefore, a mammogram is most appropriate 3-5 days after menstruation or 9-11 days after the start of menstruation. Because estrogen has the least effect on the breast at this time, the breast is in a relatively static state, there is no swelling or pain, and lesions or abnormalities in the breast are most easily detected. For women who have stopped menstruating, because there is no interference from menstruation, it is sufficient to choose a convenient time for both yourself and your physician to visit the doctor during the examination. Each self-examination should be compared with previous self-examinations, and abnormalities should be found to seek medical attention in a timely manner so as to achieve early detection, early diagnosis and early treatment.