The different sizes of breasts can be further referred to the general surgery department for breast color ultrasound examination. Some patients have bilateral asymmetry due to developmental abnormality, which is also related to activity incongruity, especially right-handed people, the right pectoralis major muscle is relatively well developed, so the right breast will be larger than the left breast. In addition, there are space-occupying lesions, commonly benign tumors, including breast fibroids or large breast lipomas, and patients may have localized lumps or mild pain. In patients with breast hyperplasia, there may be a significant difference in the bilateral breasts due to incongruous and irregular follicular hyperplasia of the breasts. Patients with malignant tumors may also have skin breakdown, axillary lymph node metastasis, and need surgery if necessary.