Recently, there are more and more patients coming to the clinic to see gynecomastia, which affects the aesthetics and creates fear and low self-esteem in many people, so to help you understand this disease, the following is an introduction. Gynecomastia, also known as gynecomastia, has a prevalence of about 30% and occurs mostly in male adolescence or old age. The pathogenesis is related to the dysfunction of various endocrine hormones or corresponding receptors in the body. For example, 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. There are two common types of the first category: 1. pubertal gynecomastia. 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 up to the size of the female breast volume. Most of them fade naturally in 1-2 years. 2. Gynecomastia in the elderly. 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. There are four common types of the second category: 1. Gynecomastia secondary to hypogonadism. It is common in men with primary hypogonadism, but also seen in men with hypogonadism secondary to pituitary or hypothalamic lesions. 2. Gynecomastia secondary to tumors. It is common in patients with testicular tumors, adrenal tumors, lung cancer, etc. 3. Gynecomastia secondary to systemic diseases. It is common 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 the aesthetic appearance, easily lead to low self-esteem, hinder daily activities, and have the risk of secondary carcinogenesis. 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 the breast development continues, medication can be applied. 2, secondary gynecomastia, the cause of the disease should first be clarified. For testicular tumors, adrenal tumors, lung cancer, hyperthyroidism, liver disease, etc., the cause should be treated first. For gynecomastia triggered by the use of certain drugs, the drug should be discontinued. For patients with hypogonadism, medications such as triamcinolone and methyltestosterone can be applied. If the above treatment measures do not work, the hyperplastic breast tissue can be surgically removed. 2, secondary gynecomastia, the cause of the disease should be clarified first. For testicular tumors, adrenal tumors, lung cancer, hyperthyroidism, liver disease, etc., the etiology should be treated first. If gynecomastia is caused by taking certain drugs, the drugs should be stopped. 3. If the above drug treatment is ineffective, the hyperplastic and enlarged breast tissue can be surgically removed.