The dangers of gynecomastia include aesthetic impact, pain, and increased risk of breast tumors. Gynecomastia may be caused by the abnormal development of male mammary glands when estrogen increases or androgen decreases in the male body, which may affect the aesthetics. In addition, the patient may have enlarged breast tissue, enlarged nipples and areolas, tenderness and other painful symptoms, and in a few cases, a small amount of white discharge can be seen when the nipple is squeezed. Continued development of the male breast also increases the risk of breast tumors. Once male breast development is detected, patients should go to the hospital in time to avoid aggravating the condition. In daily life, patients should maintain a happy mood, take appropriate physical exercise and control their weight.