Early stage breast cancer is usually asymptomatic and nothing is felt. Even for many patients, their lumps are not well-defined. When the lump is smaller than 1 cm, it may not be palpable. Not only the patient cannot feel it herself, but some doctors may not necessarily feel it even when they go to feel it. Some patients may have a vague pain, but it is not very obvious. If you are over 40 years old, you should be alert and go to the hospital for some imaging tests. Physical examination is an important method of examination that the common people call palpation by hand, which is medically called clinical palpation or physical examination. This method is generally used by specialist clinicians, and it is easy to feel accurately if the tumor is more than 1-2 cm and the location is relatively superficial. If the lump is small and deep, buried in the breast gland, and the female breast is relatively large, sometimes it cannot be felt and can only be examined by instruments. Mammogram is the standard term for a mammogram, which is the most common method of detecting breast cancer. Many large-scale studies have been done in the West to screen for breast cancer, and regular screening with mammograms in specific populations can reduce the mortality rate of breast cancer. In Eastern women, because of the relatively small size of the breast, the dense glands and the relatively low fat content of the glands, mammography alone may not be suitable for some people. In China, it is generally recommended for women to have this test after the age of 40. If there are high-risk factors, it is also possible to do it at the age of 35 or older. Generally, it is done once every two years between the ages of 40 and 50, and once a year between the ages of 50 and 60, but the time interval should not be too short, at least a year or more, if the time interval is short the X-ray itself will have some effect on the body, and doing too much has the potential to be harmful. Ultrasound examination of the breast gland in young patients is relatively dense, sometimes it is not easy to penetrate the X-ray, ultrasound can play its advantage, especially for some liquid cysts, sometimes the X-ray may not see clearly, but ultrasound can. The accuracy of the ultrasound results is closely related to the quality of the machine itself and the level of experience of the ultrasonographer. In addition, for older patients, it is better to do a supplemental X-ray examination on top of the ultrasound examination. Breast ductal endoscopy is often called a ductoscope. In women, there are usually 15-20 duct openings in the nipple. If there is a lesion inside one of them, it may produce nipple discharge. After the ductoscope is used to remove the fluid, the lesion can be seen under direct vision. It is mainly used for small tumors of one or two millimeters in diameter, which can be detected and treated by removing the ducts in some ways.