Boys can determine whether they have estrogenized breasts or fatty breasts usually by touch examination and ultrasonography. Touch to check whether the chest is fat or glandular, if it is hard to touch, it is considered to be glandular, which is estrogenized chest; if it is soft, it is considered to be fat, which is fat chest. Ultrasonography is more accurate in determining breast glandularity. Estrogenized breast is caused by increased estrogen secretion or decreased androgen-estrogen ratio, which is also known as male breast development. Patients often present with significant bilateral or unilateral breast enlargement and hypertrophy, some with tenderness. Fatty chest is formed when men consume too much energy and do not pay attention to physical exercise, resulting in excessive obesity and fat accumulation in the chest. If it is fat chest, it can be improved through weight loss and shaping. If it is estrogenized chest usually can be treated by medication, such as clomiphene citrate capsule. There are also surgical treatments, such as circumareolar mastectomy and mastoidectomy.