The risk level of breast nodules is determined by the nature of the nodule and has no clear relationship with the direction of the location of the breast, so the risk level of a nodule at 12 o’clock in the left breast needs to be analyzed on a case-by-case basis. Breast nodules can be detected by palpation, and the degree of risk can be clarified by perfecting specialized imaging such as mammogram and breast ultrasound. If the imaging shows a nodule at 12 o’clock in the left breast with clear contours, good mobility, no adhesion to the skin, and slow growth, it is generally a benign lesion. If the nodule at 12 o’clock of the left breast has unclear boundary, hard texture, poor mobility, often adheres to the skin and grows fast, and the color ultrasound suggests that the aspect ratio is more than 1 and the blood flow signal is rich, it is generally considered to be malignant, and should be punctured and biopsied in time to clarify the benign or malignant nature, and then be treated by a professional doctor. Patients who find nodules at 12 o’clock in the left breast should go to the hospital for further examination to clarify the nature of the nodules and early treatment.