A breast ultrasound 4B nodule is defined as a breast nodule with an I-RADS grading of 4B, which is defined as a substantial nodule within the breast gland and has a 30-60% chance of being malignant. Ultrasonography is the most commonly used test in the diagnosis of breast nodules, which can observe whether there is a mass in the breast gland, as well as the size of the mass, whether it is smooth in appearance, whether there is blood or calcification in the mass, and whether there is an abnormal increase in the lymph nodes in the axilla, so that a preliminary judgment can be made about the breast mass. Breast masses under ultrasound are usually categorized into 7 grades from 0-6. The higher the grade, the higher the likelihood of malignancy. Patients with breast ultrasound class 4B nodules are advised to go to a regular hospital for examination and choose further treatment options under the guidance of a doctor. At the same time, patients should not be overly nervous and follow the doctor’s instructions so as not to delay treatment.