Hard breasts are abnormal and need to be considered as breast enlargement, breast lumps or breast cancer. Most women may suffer from breast enlargement, which is mainly caused by female endocrine hormone imbalance. The typical symptoms are hard lumps inside the breasts and painful to touch. It is also associated with estrogen levels, especially before menstruation when the breast lumps become harder and more painful, and a sand-like mass of breast nodules can be touched during examination. Breast masses, if benign, are round or oval with clear borders. Breast cancer typically has lumps in the breast with unclear borders and abnormal skin changes. Mastitis and milk stagnation during breastfeeding will also show this symptom. It is better to go to the hospital breast department for examination and then treatment.