Breast disease has now become a common and frequent disease among women. The prevention and treatment of breast diseases must be done well, because it is directly related to the health of women’s breasts. The importance of the breast for women is self-evident, even if there is usually no discomfort, once a year breast examination work, is not missing. This is because there are many early breast lesions that have no clinical symptoms. When it comes to mammograms, there are two types of mammograms that are indispensable, namely mammogram and mammogram. Many patients are confused about the difference between these two types of examinations and think that mammography is just an advanced form of breast ultrasound examination. In fact, this is not the case. Ultrasound and mammography are two of the most routine basic breast examinations, and they are two completely different tests. The difference between mammography and ultrasound is as follows: 1. The principle of examination is different. Simply put, ultrasound is more sensitive to lumps, while mammography is more sensitive to calcifications. The advantages of breast ultrasound are that it is cheap, non-invasive and painless, and can be repeatedly checked without radioactivity. Mammography has a certain radiation dose, and frequent examinations are more harmful to the body and more expensive. But once a year is no problem. The mammogram can generally detect a variety of breast diseases, such as breast hyperplasia, breast fibroids, breast cysts, clinically inaccessible mass lesions, nipple overflow and so on. Early in situ breast tumors can also be detected. Especially for in situ calcified breast tumors less than 1cm in diameter, ultrasound cannot detect them, but mammography can. The main purpose of breast ultrasound is to identify the nature of a woman’s breast lump and determine whether it is a cystic or solid mass. Ultrasound can also show the fine structures inside the breast. For the dense breast that cannot be detected by mammography, it can help to discharge the tumor. For young women, ultrasound is the first choice for examination and can be repeated several times. For women older than 40 years old and young women who are considering malignant breast disease, breast ultrasound and mammography are indispensable.