It is very important for every woman to be familiar with her breasts. Self-examination of the breast is a simple and easy method of examination that can be learned by the average woman in a short period of time. The examination should be done once a month, around the 10th day of menstruation, because at this time the breast tissue is least affected by various endocrine hormones and the breast gland is relatively soft, which can reflect the lesions of the breast tissue in a more realistic and accurate way. For women who have had their ovaries surgically removed and are not menstruating or for older women who have gone through menopause, they can choose a fixed day of the month for self-examination. The examination begins with a visual examination. If possible, the upper half of the body should be completely naked, sitting upright or in front of a large mirror, and the first observation should be made in front of the mirror. You should observe whether the outline of each part of the breast is natural, whether there is bulging or depression; whether there is any change in the size of the breast; how the color of the breast skin is, whether there is redness, rash, ulceration, superficial venous anger, skin folds, orange peel-like changes, etc.; whether the nipple is elevated, retracted, depressed, whether there is abnormal discharge from the nipple; whether there is any change in the color of the areola, whether there is eczema-like change, etc. During the observation, attention should be paid to comparing both breasts and observing whether symmetry exists, especially whether the nipples on both sides are at the same level, etc. Generally speaking, if there is a new obvious asymmetry in the appearance of both breasts, it should be taken seriously enough. Also, don’t forget to look for stains left by nipple secretions on the top of the changed underwear. Next, palpation, that is, examination by hand, should be performed. You should take a sitting position or a lying position. If you take a sitting position, both arms should be relaxed and not clamped; if you take a lying position, you should put a pillow or clothing under your shoulders so that they are slightly elevated. Put the fingers of the left hand together flatly on top of the right breast, and gently touch all parts of the breast with the palm surface of the four fingers except the thumb. Be careful not to grasp and pinch the breast with your fingers to avoid mistaking normal breast tissue for a lump. The breast is divided into four quadrants: upper inner, lower inner, upper outer, and lower outer, with the nipple as the center of the horizontal and vertical lines, and the fingers should start from any of the four quadrants and move in a clockwise or counterclockwise direction to check one circle to avoid missing. If you still feel inaccurate after the 1-turn check, you can check one more turn. Then, place the right hand on top of the left breast and check the left breast again in the same way. If you find changes such as glandular thickening, nodules or even lumps in one part of the breast during the examination, you should pay attention to them. You may think, “Even if I touch a lump or lumps, I don’t know if it is benign or malignant, how can I tell? Generally speaking, when multiple small granular nodules with mild tenderness are found in both breasts, breast hyperplasia is more likely; when single or multiple round nodules with firm texture, clear border, smooth surface and high activity are found in one breast, breast fibroadenoma is more likely; when single irregular lump with hard texture and poor activity is found in one breast, you should be alert to the possibility of breast cancer. If the lump is hard and poorly mobile, you should be alert to the possibility of breast cancer. Then the nipple and areola should be examined. If there is plasma or bloody fluid, you should go to the doctor for early diagnosis and appropriate treatment. Finally, don’t forget to check both sides of the armpit. Sometimes, when a lump in the breast is too small to be touched, it has already metastasized to the axillary lymph nodes, so it is very important to check the axilla. If you have recently experienced breast discomfort or have a known benign breast disease that is being treated, you should focus on the lesion during each self-examination and compare it with the previous month to see if it has changed and if it is getting better or worse. If a lesion is detected by self-examination and confirmed by the doctor to be malignant, do not panic, but face the reality and actively treat it. You should face the reality and take active treatment. You should know that it may be because you insist on self-examination that the lesion can be detected earlier and the tumor can be cured. Therefore, you should be persistent in self-examination, do not be afraid of trouble, and do not be careless. Of course, self-examination is not a substitute for specialist examination. If you have obvious discomfort, if you find changes in breast or armpit during self-examination but are not sure of the cause, or if you are suffering from various breast diseases, you should consult a doctor and conduct self-examination and relevant specialist examination under the guidance of a doctor.