Gynecomastia can affect men of all ages and most commonly is the result of genetics, hormonal changes, certain drugs or medications, and weight gain. Gynecomastia affects approximately one out of two men at some time in their lives. This condition is characterized by excess breast fat and glandular tissue and can be present in one (unilateral) or both (bilateral) breasts. Gynecomastia can cause emotional distress and self-consciousness and many men refrain from certain activities in order to hide their condition. While losing weight may reduce the size of male breasts, because of the presence of excess glandular tissue, weight loss alone will rarely result in satisfactory breast reduction. Gynecomastia surgery or reduction mammoplasty is an effective and long-lasting way to reduce breast size, repair nipple and areola abnormalities, and improve chest contours.