Hypoechoic nodule 3㎜ with unclear border may be caused by breast diseases, such as inflammatory changes and malignant tumors. 1. Inflammatory changes: for example, acute mastitis, suppurative mastitis, ductal dilatation, granulomatous lobular mastitis, etc. These are inflammatory diseases caused by inflammatory stimulation, and the examination will show that there are breast nodules with unclear borders, good mobility of the lumps, and no adhesion with the skin tissues. 2. Malignant tumors: for example, breast cancer, mainly including carcinoma in situ and invasive breast cancer, when the cancer cells gradually spread and the swelling increases, the examination will find that there are hypoechoic nodules, with unclear boundaries, burr-like periphery, poor mobility of the nodules, and adhesion with the skin tissues. Nodule border unclear may be surrounded by inflammatory infiltration, edema, and close relationship with the surrounding tissues, so it is manifested as unclear border. Breast hypoechoic nodule border is not clear, just find out the nodule form, but can not distinguish the nature of the nodule, later it is necessary to do a pathological biopsy for diagnosis and analysis, once the detection of malignant lesions, the need for timely treatment.