Irregular breast nodules with unclear borders and no blood flow may be the result of diseases such as mastitis, cystic breast hyperplasia, and breast cancer. There are benign and malignant breast nodules, and there is no clear definition. Clinically, there are many reasons for irregular breast nodules without blood flow. Generally, benign nodules are considered, such as mastitis, which is related to pathogenic bacterial infections, breast trauma, drug stimulation, etc. In the early stage of the disease, hard nodules with unclear borders can be found in the breasts through examination. Secondly, it may also be cystic breast hyperplasia, related to endocrine disorders, usually multiple cystic breast hyperplasia will exist irregular, different shapes of nodules. However, malignant nodules, i.e. breast cancer, cannot be ruled out, mainly because the blood flow of breast cancer is more abundant, and breast cancer nodules usually have unclear borders and may have adhesions with the surrounding tissues. It is recommended that patients with irregular breast nodules with unclear borders and no blood flow should undergo further pathological examination to clarify the specific causes so as not to delay the condition.