The pain on the right side of the male nipple may be due to the following conditions: first, breast enlargement, because the initial symptom when breast enlargement occurs is breast pain, which is also accompanied by breast lumps, overflowing discharge and poor temperament. second, it may be nipple inflammation, that is, nipple lesions, which need to be examined to confirm the diagnosis. Third, it may be due to pain caused by inflammatory breast infection, especially acute mastitis and acute suppurative inflammation, some patients will have nipple swelling and pain with local tenderness. Fourth, it may be due to pain caused by breast fibroids, which are abnormal growths of fibrous tissue, and a few patients will have nipple pain. Considering that the causes of pain on the right side of the male nipple are more complex, it is best to go to the breast department of the hospital for further examination.