Gynecomastia is the development of prominent breast tissue in the male. The condition can develop during puberty and sometimes resolve on its own. Other causes of gynecomastia include exposure to estrogens, androgens (often taken secretly for body building), marijuana, and some medications. Rare causes include tumors, genetic defects, and chronic liver disease.
Review Date 10/11/2018
Updated by: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.