Hard lumps under the nipple in male puberty may be normal, or it may be triggered by factors such as breast trauma or breast cancer. 1. Normal phenomenon: male puberty hard lumps under the nipple, mainly and puberty endocrine disorders related to the male in puberty, the body’s level of estrogen may rise, will lead to hard lumps in the nipple. With the development of the body, androgen levels will continue to rise, estrogen levels will slowly decline, the hard lumps under the nipple will slowly disappear. 2. Breast trauma: hard lumps under the nipple in male puberty may also be caused by impact on the mammary gland, rupture of local capillaries and obstruction of blood circulation. 3. Breast cancer: If you have breast cancer, with the development of the disease, it will cause hard lumps under male nipples, which may also be accompanied by abnormal changes in the local skin, poor mobility of the lumps, unclear boundaries and other symptoms. Male adolescent hard lumps under the nipple should also consider inflammation, benign tumors, chest wall diseases and other causes, and can not be a single through the body’s symptoms to judge, but also need to go to the hospital for relevant examinations, for the cause of the treatment.