Hard lumps in male breasts are usually abnormal and may be caused by gynecomastia, mastitis, breast tumors, etc. If you are in puberty, it may be a normal phenomenon. 1. Gynecomastia: If the level of estrogen in the male body is too high, and the ratio of estrogen and androgen is out of proportion, it may cause abnormal development of the male mammary glands, and the patient will mainly have breasts in nodular or discoidal hyperplasia and enlargement, and some of the patients will have a sense of pain to touch. 2. Mastitis: Men can also suffer from mastitis, but it is relatively rare. Patients will have symptoms of breast swelling and pain, and may also have breast lumps, often accompanied by pressure pain. 3. Breast tumors: In addition to mastitis, men may also develop breast tumors, which may be associated with a family history of cancer, trauma, and excess estrogen. The symptoms are similar to those of women, with painful breast lumps and rapid growth. Meanwhile, breast hyperplasia, breast fibroadenoma, and breast trauma can all present with a hard lump in the breast. If the patient is in puberty, because of hormone secretion, there will be breast hyperplasia and breast development, which can usually recover by themselves. It is recommended that patients go to the hospital for examination in time, clarify the cause of the disease with the help of doctors, and then carry out targeted treatment.