With the development of the times, people pay more and more attention to medical checkups. Among the medical checkups for women, mammography is one of the tests that can detect any abnormalities in the breast in time. Here, we will explain the importance and role of breast ultrasound. Ultrasound is mainly used to examine lobular hyperplasia, inflammation, cysts, fibroids and breast cancer, especially to identify the benignity and malignancy of breast lumps, to detect early breast cancer, and to check whether there are enlarged lymph nodes in the axilla and clavicle. The increasing improvement of ultrasound imaging technology, especially the emergence of color Doppler ultrasound technology, enables the internal structure, size, shape, edges, the number of internal blood vessels, blood flow distribution, and its relationship with surrounding tissues of breast lumps to be clearly displayed. Based on these detected data, doctors can initially determine the nature of the lump. In short, whenever a lump is found in the breast, the nature of the lump can be initially clarified through ultrasound examination. Role of breast ultrasound: 1. Observe the shape of breast lumps. Breast cancer lumps often have unclear borders or irregular shape on ultrasound. 2. To observe the condition of supraclavicular and axillary lymph nodes. Under normal circumstances, the lymph nodes in these two areas are not enlarged. If a breast lump is found and the lymph nodes in these two areas are enlarged at the same time, and no other cause of the enlarged lymph nodes can be found, it should be suspected that the breast lump may be malignant and may have metastasis. 3. Calcification sound image in the lump. The calcification of breast cancer is characterized by pinpoint-like or mud-like microcalcifications. Due to the high resolution of ultrasound, it is easy to detect the calcification within the lump. 4. Blood flow in and around the lump. Breast cancer can produce tumor angiogenic factor, which stimulates angiogenesis and forms a rich vascular network inside and outside the tumor. Ultrasound can detect more blood color in or around the lump.