Breast Swelling in Males Underlying Cause
The most common cause of gynecomastia is puberty. However, the breast enlargement resolves as puberty progresses.
Additional causes of gynecomastia include:
- Bembo SA, Carlson HE. Gynecomastia: its features, and when and how to treat it. Cleve Clin J Med. 2004 Jun;71(6):511-7. 
- Harigopal M, Murray MP, Rosen PP, Shin SJ. Prepubertal gynecomastia with lobular differentiation. Breast J. 2005 Jan-Feb;11(1):48-51. 
- Prisant LM, Chin E. Gynecomastia and hypertension. J Clin Hypertens (Greenwich). 2005 Apr;7(4):245-8. 
- Wiesman IM, Lehman JA Jr, Parker MG, Tantri MD, Wagner DS, Pedersen JC. Gynecomastia: an outcome analysis. Ann Plast Surg. 2004 Aug;53(2):97-101.