Breast nodules going from grade 3 to 4a is more serious. A grade 3 to 4a breast nodule is usually a malignant nodule found in the breast. When a patient develops a grade 4a breast nodule, further investigations, including a biopsy, are needed to determine whether the nodule is benign or malignant. If the breast nodule is benign, then it is not a big problem and can be treated with surgical excision under the guidance of the doctor according to the patient’s specific situation. However, if the breast nodule is malignant, further examination is needed to clarify the stage before comprehensive treatment, which generally includes surgery, radiotherapy and chemotherapy. When breast nodules change from grade 3 to 4a, patients should immediately go to regular hospitals for a comprehensive examination to determine the cause of the disease and then follow the doctor’s instructions for treatment.