Gynecomastia, also known as gynecomastia and gynecomastia, is the excessive development and enlargement of one or both of the male breasts, with a female appearance. Some patients have painful swelling and swelling, and swelling-like masses can be found under the areola, and milk-like overflow can sometimes be seen when the nipple is squeezed. In gynecomastia, there is no histological hyperplasia of the alveoli, only hyperplasia of the ducts and hypertrophy of the fibrofat between the ducts. Disorders of the testes, adrenal glands and hypothalamus-pituitary gland, liver function impairment, and long-term related medications (e.g. spironolactone, estrogen, metformin, etc.) can all cause gynecomastia. The result of this disorder is an imbalance in the ratio of sex hormones in the body and a relative increase in estrogen concentration. Based on the reference to the typology of gynecomastia, gynecomastia is divided into three categories from a pathological and clinical point of view: fatty, glandular and mixed. The practice of subcutaneous glandular excision alone may not be in line with today’s trend of minimally invasive and effective cosmetic surgery. According to the typology of gynecomastia, three types of surgery are available: breast liposuction, subcutaneous glandular excision, and breast liposuction + subcutaneous glandular excision. Fatty gynecomastia is dominated by subcutaneous fat hyperplasia and is suitable for the practice of breast liposuction; glandular gynecomastia is dominated by glandular hyperplasia and is suitable for subcutaneous glandular excision; and mixed gynecomastia. In the case of glandular and fatty hyperplasia, a single liposuction cannot achieve a complete and effective breast reduction, while subcutaneous adenomectomy bleeds too much. Effective postoperative drainage and dressing should not be neglected. Patients are routinely asked to wear a pressure dressing on the chest for one week and a tight-fitting top for three months after surgery.