The female breast is a functional organ and is likened to the source of life. The female breast is also a physical organ and is one of the most prominent signs of female beauty. People always think that breast disease is the exclusive preserve of women, but this is not true, men can also suffer from breast disease. The male breast is not mature, but this does not mean that men do not have a breast. Some men have enlarged breasts for various reasons, even like women, which is medically called gynecomastia. In addition to enlarged breasts, sometimes there is localized pain or milk-like discharge, although male breast disease is not common, but once the disease, the patient will be affected physically and mentally, which makes the patient feel embarrassed, and even mentally depressed and eager for treatment. The causes of male breast disease can be simply summarized into two points: the absolute or relative increase of estrogen levels in the body and the increased sensitivity of breast tissue to estrogen. Normally, male testes not only produce androgens, but also estrogen, and estrogen and androgen maintain a certain ratio in the body. If this balance is disturbed for some reason, excess estrogen can stimulate the growth of breast ducts and cause male breast disease. There are generally primary and secondary forms. Primary gynecomastia is usually due to a physiological endocrine disorder and can be seen in newborns, adolescents, and middle-aged and older patients, with adolescent development being the most common. The incidence of gynecomastia in young men is estimated to be as high as 38%. Gynecomastia occurs when testicular function decreases and androgen production decreases while estrogen remains at normal levels as we age. In the elderly, gynecomastia is more likely to occur in the obese elderly because the peripheral adipose tissue can cause an increase in serum estrogen. Secondary gynecomastia refers to endocrine dysfunction due to a primary cause, which leads to breast development, usually in middle-aged and older patients. Secondary gynecomastia can be caused by a variety of diseases or medications, including diseases that produce excessive estrogen, such as hermaphroditism, testicular tumors, adrenal cortical masses, lung cancer, liver cancer, liver cirrhosis, etc.; diseases that reduce androgen production, such as primary testicular insufficiency, trauma, orchitis, radiation therapy, kidney failure, etc.; and also by the use of certain medications that cause gynecomastia, such as growth hormone, digitalis, estrogen, etc. The common clinical symptoms of gynecomastia are usually the gradual enlargement of the breasts. In adolescent gynecomastia, it is usually bilateral and symmetrical and can be combined with varying degrees of pain or discomfort, with disc-shaped or nodular masses palpable under the nipples and areola, with clear borders, medium hardness and smooth edges. In older men, gynecomastia is often unilateral, with a mass under the areola that may be irregular in shape and may be associated with pressure pain. Male breast development can be divided into the following three types: 1) glandular, where the enlarged breast is dominated by glandular hyperplasia; 2) fatty, where the enlarged breast is dominated by fatty tissue hyperplasia; 3) glandular-fatty, where both glandular and fatty tissue are hyperplastic in the enlarged breast. We can usually perform a color ultrasound examination of the breast in the hospital, which is the most routine test to confirm the diagnosis of gynecomastia. This is the most routine test to confirm the diagnosis of gynecomastia. Secondly, MRI and mammography of the breast are also auxiliary tests that can help us determine the nature of the lesion and decide on the next step of treatment. The first thing you need to do is to have a scientific understanding of the disease once you have enlarged breasts in men. Physiological gynecomastia is usually self-healing. If it is caused by drugs, it can subside after stopping the medication. For pathological gynecomastia, the cause should be addressed by actively treating the primary cause, regulating endocrine, and at the same time treating the symptoms. It is important for patients to put down their ideological baggage and actively cooperate with the treatment. If long-term conservative treatment is ineffective and the breasts are too large, distended and painful, or if cancer is suspected, they can be surgically removed. To completely cure gynecomastia, surgery is the only effective method. However, surgical treatment requires attention to the following issues: First, cure requires total excision of the gland, especially the closely adherent glands behind the nipple areola. Removing the glands cleanly in these areas carries the risk of causing necrosis of the nipple areola, with a probability of less than 5%, but the risk of color change of the nipple crust is close to 10%. Second, total excision of the gland tends to lead to postoperative fluid accumulation in the chest, delaying the prognosis of the wound. The probability of occurrence is about 5-10%. Third, the chest wall may be sunken and change like a crater after surgery. This complication is more likely to occur in fat people. However, it will gradually get better. Fourth, postoperative decrease or loss of skin sensation in the nipple areola and other areas. This is associated with damage to the nerve fibers that innervate the skin and nipple areola area. A significant percentage can also recover slowly. When you are aware of the above and can accept the eventuality of the above complications happening to you, you can opt for the surgery. If, in the unlikely event that they occur, you cannot accept them, then you choose to be closely observed. As long as there are no nodules, calcifications, or lumps in the gland, you can be closely observed. Now with the innovation of technology, our hospital adopts a small incision in the areola (for average size of breast development) or a crescent-shaped surgical incision (for those with extra large breast development) to remove the developing glandular tissue through a small incision next to the areola. This surgery is less damaging, aesthetically pleasing and suitable for most gynecomastia patients. Due to the lack of awareness of gynecomastia and the lack of regular self-examination of the breast in men. Gynecomastia can cause male breast cancer, so many male breast cancer patients are often found late, so that many patients lose the opportunity of treatment, and their prognosis is worse than female breast cancer. Therefore, it is recommended that men should also have regular self-examinations of the breast and go to the hospital for treatment in time if abnormalities are found.