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.
Nancy J. Rennert, MD, Chief of Endocrinology & Diabetes, Norwalk Hospital, Associate Clinical Professor of Medicine, Yale University School of Medicine, New Haven, CT. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.