Breast nucleus is a normal physiological phenomenon, while hard lumps are usually caused by breast hyperplasia, mastitis, breast cancer and so on. 1. Nucleus: Nucleus is a normal tissue in the human body, which is usually not accompanied by abnormal symptoms and will not affect your health. Nucleus does not require special treatment, and daily care of the breast area can be strengthened. 2. Hard lumps: usually refers to hard lumps in the breast, which are considered to be related to breast hyperplasia, mastitis, breast cancer, breast fibroadenoma and so on, which are abnormal phenomena. In addition to lumps, patients are also prone to breast pain, nipple discharge, axillary lymph node enlargement and other symptoms, which affects the quality of life and should also affect the health of the organism, so patients need active treatment. In addition to the above differences, those with breast nuclei usually have no abnormalities in the medical examination, while those with breast lumps may have abnormalities in blood tests, chest CT and other tests. If you want to know whether it is a breast nucleus or a lump, you can go to a regular hospital for examination, so that you can clarify the specific situation and cooperate with the doctor for active treatment.