Regular breast self-examination is one of the self-care methods for women. If any abnormality is found in self-examination, timely medical consultation can detect breast cancer earlier. How to do breast self-examination: Stand or sit in front of the mirror, face the mirror and carefully observe both breasts, including the size, shape, outline, skin and color of breasts, whether there is any change, whether the nipples are elevated, retracted or overflowing. Touch your breasts with your fingers, the right side with your left hand and the left side with your right hand, either in a clockwise or counterclockwise direction, not missing the nipples, areolas and armpits. Breast self-examination should be done once a month, choosing a time when the relative physiological condition is the same. The best time should be chosen around the 10th day after menstruation, when the breast is relatively soft and painless, and it is easy to find abnormalities. For women who have stopped menstruating, a fixed time of the month can be chosen for the examination. Each self-examination should be compared with the previous self-examinations, and abnormalities should be found to seek medical attention in time to achieve the purpose of early detection and early diagnosis.