Gynecomastia is classified as physiological or pathological. Physiological gynecomastia is most common in newborns, adolescents, and menopause, and can be self-healing. Pathological gynecomastia is called gynecomastia. Gynecomastia is a disorder characterized by enlargement of the male breast, unilateral or bilateral lumps, sometimes accompanied by pain and swelling. The disease is most common in middle-aged and older males, but can also occur in boys around the age of 10. Although this disease is not common clinically, it causes great psychological stress to patients and affects their normal life, so timely, accurate and effective diagnosis and treatment of this disease should not be taken lightly. How does gynecomastia occur? Gynecomastia occurs mainly due to an absolute or relative increase in the level of estrogen in the body, or due to an increase in the sensitivity of breast tissue to it. Both males and females secrete both androgens and estrogens, but only the ratio is different to reflect the difference in gender. For example: 1. Diseases of the adrenal cortex, the main secretion site of estrogen, can cause abnormal increase in estrogen levels; 2. When the liver, the site of estrogen metabolism, is diseased and has decreased liver function, estrogen can accumulate in the body and cause the disease; 3. The disease can occur in the testes. Other diseases such as hypothalamic-pituitary disorders, thyroid disease, diabetes, abnormal sexual development, chronic colitis, etc. can also lead to this disease. Some drugs such as progestins, isoniazid, tricyclic antidepressants, digitalis, etc. can affect estrogen metabolism and induce breast enlargement. Third, how to treat? 1. Etiological treatment: If the cause is clear, the primary cause should be treated, such as tumor removal, discontinuation of drugs that cause breast enlargement, such as haloperidol, and androgen replacement therapy for those with hypogonadism. 2.Medication: The following drugs can be used clinically: (1) Danazol: It is a weak androgen, which plays a therapeutic role by inhibiting gonadotropin secretion. The dose is 200 mg three times a day for 3-9 months. It is effective for both adult and adolescent mastopexy, with side effects such as weight gain. (2) Triamcinolone acetonide (tamoxifan): It is an estrogen receptor blocker at a dose of 10 mg twice daily for 3 months, with an efficiency of 88%. (3) Clomiphene: also an anti-estrogen agent, 50 mg daily, about half of the effective. (4) Dehydrotestosterone (testolactone): It is an aromatase inhibitor at a dose of 450mg per day, and the estrogen/androgen ratio decreases after administration. (5) Anastrazole: It is a new type of aromatase inhibitor, which has been used to treat postmenopausal breast cancer patients and is now clinically proven to be safe and effective in the treatment of gynecomastia. This drug inhibits tissue estrogen secretion and reduces estrogen production, without inhibiting pituitary function. Side effects include flushing, thinning of hair, gastrointestinal reactions (anorexia, vomiting, diarrhea), etc. 3.Surgical treatment. Indications for surgery include: (1) Men with breast development at the end of puberty or after puberty, with breast diameter >4cm, and drug treatment is ineffective. (2) Seriously affect the aesthetic appearance. (3) Those with suspected malignant changes. IV. What is the prognosis? The prognosis of this disease is good, the milder ones can be cured by themselves, the more serious ones can be cured after taking medicine, and those who have failed in long-term conservative treatment can be cured after surgery. V. How to prevent? Cultivate the body and keep a comfortable mood; strengthen physical exercise, abstain from sexual intercourse, avoid overwork; eat nutritious and easily digestible food, avoid fatty, cold and irritating food; actively treat various primary diseases; cautiously use drugs that may disrupt endocrine secretion.