Gynecomastia, also known as male gynecomastia, has a prevalence of about 30% and occurs mostly in male adolescence or old age. The pathogenesis is related to the imbalance of various endocrine hormones in the body. The pathogenesis of gynecomastia is related to various endocrine hormone disorders in the body, such as increased or relatively increased estrogen levels, or increased sensitivity of estrogen receptors in breast tissue to estrogen, or defective androgen receptors. Depending on the cause, gynecomastia can be divided into two categories: primary gynecomastia and secondary gynecomastia. The first category includes two types: 1. Gynecomastia during puberty. The onset is mostly in adolescent males (12-20 years old), and about 80% of them develop bilaterally. A 2-3 cm disk-shaped mass is often formed under the areola and gradually develops, even reaching the size of the female breast. Most of them fade away naturally in 1-2 years. 2.Geriatric gynecomastia. The onset is mostly in older men (50-70 years old). It starts as an enlargement of one breast, often forming a 2-4 cm lump under the areola with clear borders. It mostly resolves spontaneously within 1 year. The second category includes four types: 1, gynecomastia secondary to hypogonadism. It is commonly seen in men with primary hypogonadism, but also in men with hypogonadism secondary to pituitary or hypothalamic lesions. 2. Gynecomastia secondary to tumors. Commonly seen in patients with testicular tumors, adrenal tumors, lung cancer, etc. 3. Gynecomastia secondary to systemic diseases. Commonly seen in patients after hemodialysis treatment, impaired liver function, hyperthyroidism, hypoadrenalism, etc. 4, drug-related gynecomastia. Commonly seen in patients suffering from prostate hyperplasia who have been taking estrogen for a long time, patients suffering from gastric disease who have been taking metformin for a long time, etc. In addition, many obese men have more fat content in their breasts, which can also manifest as bilateral breast enlargement and augmentation. For gynecomastia patients, enlarged breasts affect aesthetics, cause low self-esteem, hinder daily activities, and have the risk of secondary cancer. Therefore, early diagnosis and timely treatment is very important. But how to treat different causes of gynecomastia? 1. Primary gynecomastia is mostly temporary and can subside on its own, so there is no need to rush to treat it. If breast development persists, it can be treated with drugs such as triamcinolone and methyltestosterone. If these medications are not effective, the hyperplastic breast tissue can be surgically removed. 2, secondary gynecomastia, first of all, the cause of the disease should be clarified. For testicular tumors, adrenal tumors, lung cancer, hyperthyroidism, liver disease, etc., etiological treatment should be performed first. For gynecomastia triggered by the use of certain medications, the medication should be discontinued. For patients with hypogonadism, medications such as triamcinolone and methyltestosterone can be applied. If the above treatment measures are ineffective, the hyperplastic and enlarged breast tissue can be surgically removed. 3. Surgery is usually performed by using a curved incision at the edge of the lower 1/2 areola to completely peel and remove the enlarged and hypertrophied glandular tissue. After surgery, the chest is bandaged with pressure.