There are many causes of nipple pain in 14-year-old boys, such as physiological phenomenon, nipple inflammation, breast cancer and so on. 1. Physiological phenomenon: most of the 14-year-old boy nipple pain is due to mammary gland dysplasia, this stage of the boy belongs to the period of growth and development, due to the influence of the body’s hormone level can be caused by nipple pain, usually after puberty will gradually ease. 2. Nipple Inflammation: Boys nipple suffers from bacterial infection, can induce acute nipple inflammation, so it can show nipple pain, accompanied by local redness and swelling phenomenon. 3. Breast cancer: Boys can also suffer from breast cancer risk, which can show nipple pain, accompanied by breast tumors and other phenomena. At the same time, nipple pain in 14-year-old boys may be the cause of breast enlargement, skin disease, trauma and so on. There are many causes of nipple pain in 14-year-old boys, it is recommended to go to the hospital in time to improve the examination and clear diagnosis, and not to ignore the symptoms and take them lightly, so as not to delay the treatment of the condition.