Under the skin of normal breasts are fatty tissue and breast glandular tissue, which in turn includes lobules, ducts, and follicles. These tissues can form a vague granular, pliable, and elastic soft tissue that is located in the middle of the breast and usually does not have a hard lump and is not associated with pain or other discomfort. Hard lumps in the breast may be caused by diseases such as fat necrosis, milk stasis, cystic hyperplasia, fibroadenoma, intraductal papilloma, and breast cancer, etc. Patients can make a judgment with the corresponding accompanying symptoms and should seek medical attention if disease is suspected. The common clinical diseases with breast lumps and their manifestations are as follows: 1. fat necrosis of the breast: mainly due to violent injury to the breast resulting in necrosis of fatty tissue, usually accompanied by local tenderness in addition to hard lumps in the breast; 2. milk stasis: in the case of lactating women, failure to empty the milk in a timely manner can result in the accumulation of milk in the milk ducts and the formation of hard lumps, sometimes accompanied by mild pain, and if infection occurs, local redness, swelling, pain and swelling can occur. 3. Cystic hyperplasia of the breast: mostly related to abnormal hormone levels, the main symptoms are hard lumps in the breast and painful swelling or tenderness, which are mostly related to the menstrual cycle, appearing or worsening before menstruation and decreasing or disappearing after menstruation; 4. In addition to hard lumps in the breast, there are often no other obvious conscious symptoms, and the hard lumps have a smooth surface and are easy to push, with a texture that resembles the elasticity of a hard rubber ball. In addition to nodules or hard lumps in the breast, it is usually accompanied by nipple overflow, which is mostly bloody, dark brown or yellow liquid; 6.Breast cancer: it is related to various factors, such as hormones, radiation, long-term emotional problems, genetics and poor lifestyle, etc. It can often appear as a hard, non-smooth lump in one or both breasts, and the nipple can be sunken, flattened or retracted with the development of the disease, and the local skin is The skin may be dimpled, flattened or retracted, and the skin may be dimpled or orange peeled.