Whether a breast nodule 7x3mm is serious depends on the nature of the nodule; benign nodules are not serious and malignant nodules are more serious. 1. Benign nodules: such as breast fibroadenoma, intraductal papilloma. Benign nodules can be painful to touch, and under ultrasound examination, benign nodules often have clear boundaries, regular morphology, and are not rich in blood flow signals. 7x3mm benign breast nodules are relatively small, and patients with no serious clinical symptoms can be followed up with observation without special treatment. 2. Malignant nodule: i.e. breast cancer. Malignant nodule is usually painless, and under ultrasound examination, the nodule has the characteristics of unclear boundary, uneven density, necrosis and rich blood supply, etc. 7x3mm malignant breast nodule should be treated immediately once it is detected, otherwise, the tumor will increase or metastasis will threaten the patient’s life, and the breast cancer is often treated by radical mastectomy, radiotherapy, chemotherapy and other ways of treatment. Breast nodule 7x3mm should go to the hospital in time, to clarify the nature of the nodule, according to the nature of the nodule is different to take different treatment programs, benign and malignant breast nodules can not be identified should be further pathology puncture examination.