The hard lumps in the breasts after one year of weaning may be caused by incomplete return of breast milk and milk stagnation, or it may be caused by mastitis, breast hyperplasia, breast tumors and other diseases, which should be examined in the hospital immediately and treated with physical, medication, or surgical treatment under the doctor’s guidance. 1. Breast milk stagnation: most of the hard lumps of breast milk stagnation can be absorbed by themselves, you can use towels and hot compresses to promote the absorption of the hard lumps, if there are symptoms of pain, you should use the breast pump in a timely manner to suck out the breast milk as much as possible, so as not to cause inflammation. 2. Mastitis: When the milk is stagnant and causes an infection, hard lumps will also form. The first thing to do is to empty the breast milk, and then use drugs such as benzoxiline sodium and cefradine to treat and eliminate the infection. 3. Breast Hyperplasia: Patients with breast hyperplasia will also have breast lumps. The disease is usually treated symptomatically, and patients can use medicines such as Sanjieling capsule, Breast lump elimination tablets, and Breast Ning tablets to alleviate the symptoms. 4. Breast tumor: patients with breast tumor will also have breast lumps, and should seek medical advice in time to clarify the nature of the tumor, benign can be followed up and observed, malignant to surgical resection, and may also need to cooperate with chemotherapy, targeted therapy, endocrine therapy and so on. There are many diseases that cause hard lumps in the breast, so we suggest that patients should consult a doctor in time for examination, make a clear diagnosis, and then carry out the corresponding treatment under the guidance of the doctor.