Breast nodule grade 3 with poorly defined margins and regular pattern refers to the result of breast ultrasound examination, which is considered to be more likely to be benign. Breast ultrasound is an examination tool mostly used for preliminary determination of the benign and malignant nature of breast nodules, in which grade 1-3 is mostly considered benign, and grade 3 breast nodules with unclear margins and regular shape are mostly considered benign, with malignant rate not exceeding 2%, and the lack of clarity may be due to the presence of oedema or inflammatory infiltration around the nodule, which does not need puncture examination and surgical treatment for the time being, but should be rechecked every 3 months or half a year. If the ultrasound result is more than grade 4, and there is blood flow in the nodule, unclear boundary, etc., you should be alert and go to the hospital for puncture examination or surgical excision in time. In daily life, you should keep your mood relaxed and avoid trauma. If you find hard lumps or breast pain, you should go to the hospital in time to find out the cause of the disease, and the doctor will give you targeted treatment.