There is a certain relationship between breast nodules and breast cancer. Usually, the size, mobility, echogenicity and blood flow of breast nodules can be seen under ultrasound or mammogram, which has a certain value for the diagnosis of the disease, but the exact diagnosis requires pathological biopsy or aspiration cytology to make a clear diagnosis, which is reflected in the following aspects: First, if the breast nodules are usually less than 3 cm or smaller, with an intact envelope, smooth surface, grayish, solid and tough surface, they are usually benign after pathological testing, such as breast fibroadenoma, intraductal papilloma and other lesions. First, if the nodule is usually less than 3 cm or smaller, with an intact envelope, smooth surface, and a gray, solid, tough cut surface, it is usually a benign nodule after pathological testing, such as breast fibroadenoma, intraductal papilloma, and other lesions. Secondly, if a breast nodule has poor mobility, no envelope, poorly defined from the surrounding breast tissue, with grayish white, grayish red, solid and hard surface, it is usually a breast cancer under pathological examination. Thirdly, if breast nodules keep increasing in size under the stimulating effect of various factors, they may also become cancerous, such as lobulated cystic sarcoma. Therefore, there is a relationship between breast nodules and breast cancer. Patients are advised to have regular checkups for early detection and early treatment to avoid delaying the disease.