A small hard lump at the chest is considered to be one of the following conditions. First, it may be suffering from breast disease. Among them, when you have mastopathy, there will be a hard lump on your breast, which is painful to touch, with overflowing nipples, especially before the physiological period when the pain is increased and the hard lump is enlarged. When you have mastitis, the symptoms are hard lumps, redness and pain in the breasts; when you have breast cancer, you also have hard lumps in the breasts and the pain is more intense, or it may be breast fibroids, etc. Secondly, it may be lipoma or sebaceous cyst. These tumors need to be distinguished as benign and malignant. If they recur, they can cause infections and are accompanied by fever and painful sensations. Finally, it may also be due to boils on the chest, etc. It is recommended to go to the relevant departments of the hospital for further examination and, if necessary, surgical treatment by excision.