Breast cancer is a serious threat to women’s health all over the world, so it is important to start with prevention. The incidence of breast cancer increases rapidly after the age of 20, and even breast cancer can occur in men, so what are the early signs of breast cancer that should be noticed? Early signs of breast cancer I. Asymmetry of both breasts: Due to the presence of tumor or adhesion to the chest wall, there may be changes in volume or shape of the breast on that side. Early signs of breast cancer II, nipple overflow: the nipple overflows with milky white, yellowish, brown or bloody, watery or purulent fluid during non-lactation period. Early signs of breast cancer III, nipple changes: When the tumor invades the nipple or the subareolar area, it leads to nipple distortion, retraction, sunken, etc. Early signs of breast cancer IV. Breast pain: A few breast cancer patients have hidden pain, stabbing pain, swelling pain or dull pain in the breast.