The 26-year-old male mammary gland development can not be treated if it is physiological mammary gland development, if it is a pathological factor to receive timely treatment. The causes of male mammary gland development include physiological and pathological, of which physiological mammary gland development is mostly seen in adolescent males, for this kind of mammary gland development should consult a doctor for examination in a timely manner, no special treatment is needed, and usually minimize the consumption of estrogen-containing foods, such as fried foods and other foods. Pathological gynecomastia can be caused by a variety of reasons, such as liver hypoplasia, testicular cancer and so on. It is important to seek timely medical treatment, have a professional doctor to determine the cause of the disease, according to the cause of the treatment. The 26-year-old male breast development should seek medical treatment in time, have a professional examination, and receive treatment in time if it is a pathological cause.