There are several ways to check for nodules in the breast, the first method is to check by hand, which is convenient and simple, saving costs, but the sensitivity of the hand is poor, if the hand can feel something at least 2cm or more, if the breast is full, it is more difficult; if the breast is flat, it may be easier to feel. The first method is ultrasound, called ultrasound, which can detect nodules <1cm and can be done at any age, but this is related to the condition of the machine and the operator's skill. The second method that is more accurate than the hand is mammography. Mammography is still relatively popular in Europe and the United States, but there are some cases where it is not possible to use it, for example, if the breast is flat, it is not possible to see the breast, and it is not easy to see the denser breast. So these two methods are used in combination, not to say which is better, they both work together to do. The third method that is more accurate than the hand is the MRI, because not every hospital has an MRI machine, and not every machine is equipped with a special coil for mammography, and the mammography, the cost is still relatively high. The MRI examination time is longer, taking half an hour, and the MRI is not preferred. The vast majority of young people prefer to do color ultrasound, 35 years old, 40 years old and above, color ultrasound and mammography combined to check and see better.