In men, ductal structures are also present behind the nipples and areolas, except that there are no glandular lobules due to the lack of estrogen in the body. Therefore, males can also have breast disease. Common male breast disorders include gynecomastia, also known as gynecomastia or gynecomastia. The disease is most often seen around puberty and in old age. There are several causes, such as excessive estrogen, insufficient androgens, pituitary adenomas, testicular tumors, and liver disease. Breast enlargement may also occur in patients taking estrogen for prostate disease. It can occur unilaterally or bilaterally, with a medium texture and less frequent nipple discharge. The extent of hyperplasia can be 1-2 cm, or about the size of an adult female breast. The diagnosis can be made by ultrasonography. Regarding treatment, the first step is to identify the cause and treat it symptomatically. Patients who do not have a cause, but have significant enlargement that affects their appearance, can be surgically removed. Surgery can be done either by traditional open surgery or by minimally invasive lumpectomy. In addition to gynecomastia, men are also at risk for breast cancer, which accounts for about 1% of the incidence of breast cancer in men. Male breast cancer is also the main disease to be differentiated from gynecomastia. The clinical manifestations of male breast cancer are the same: palpable swelling behind the nipple and areola, most of which are painless and may be accompanied by nipple indentation, nipple overflow and orange peel sign. Ultrasonography and histopathological examination can be performed to confirm the diagnosis. The treatment of male breast cancer is basically the same as that of female breast cancer, which is a combination of surgery and other treatments depending on the specific condition.