Gynecomastia

Gynecomastia /ˌɡaɪnɨkɵˈmæstiə/ is the benign enlargement of breast tissue in males. It may occur transiently in newborns. Half or more of adolescent boys have some breast development during puberty. Gynecomastia may arise as an abnormal condition associated with disease or metabolic disorders, as a side-effect of medication, or as a result of the natural decrease of testosterone production in older males. In adolescent boys, the condition is often a source of psychological distress; however, 75% of pubertal gynecomastia cases resolve within two years of onset without treatment.