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 10/2/2020
Updated by: Brent Wisse, MD, board certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.