Gynecomastia is a benign proliferation of breast tissue in males. It can be unilateral or bilateral, and may be attributed to many different causes, though idiopathic gynecomastia is the most common presentation. Gynecomastia can also develop during periods of hormonal change and imbalance, in response to certain medications, or as a result of pathologic causes, such as testicular tumors, hormonal or endocrine abnormalities, or genetic disorders such as Klinefelter syndrome. There are several classification systems for gynecomastia—most provide a grading scale based on degree of breast hypertrophy as well as skin laxity. Nonsurgical treatment is aimed at identifying the underlying cause of gynecomastia. Persistent gynecomastia can be addressed surgically, most frequently with suction assisted lipectomy or periareolar mastectomy with or without skin excision. Hematoma and under-resection are frequently cited complications of surgery.