The key to self-examination is to detect changes in the breasts. Self-examination of the breasts is best done once a month, as the state of the breasts changes with the menstrual cycle. It is best to check at the same time of the month, within a week of menstruation. If you are already in amenorrhea, self-check can be done on the same day of the month according to the calendar. Observe the size and shape of the breasts to see if they are symmetrical, and whether there is any inflammation, water, orange peel, or other changes in the skin. Observe whether the veins in the mammary glands area are enlarged, whether the position of nipple is equal on both sides, whether there is nipple retraction, ulceration, nipple overflow, etc. Whether the color of areola is uniform or not, and whether the shape is round or not. 2, breast palpation When checking the five fingers together, use the palm surface of the fingers and the front part of the palm to touch on the breast. When checking the left side, use the right hand, and when checking the right side, use the left hand, do not grab and pinch the breast, so as not to mistake the normal breast tissue for a breast lump. The order of touching is counterclockwise, starting from the inner upper, followed by the inner lower, outer lower, outer upper quadrant, areola area, and finally the end of the gland, so as not to miss, and the palm of the hand needs to be used with a certain amount of pressure. During palpation, attention should be paid to the mobility of the breast, the presence of tenderness, and the presence of a lump.