Who Develops Gynecomastia?
Print PageThe most likely males to develop gynecomastia are newborns, pubescent boys, and elderly men because their hormones are in transition. Between 60% and 90% of newborn boys develop temporary gynecomastia because of exposure to their mothers’ estrogen hormone.
About 65% of adolescent boys experience transient gynecomastia as a normal part of puberty. The peak time is 14 to 14.5 years of age.
About 15% of adult men worldwide have gynecomastia.
Two-thirds of affected men have bilateral (on both sides) gynecomastia. One-third of affected men have unilateral (one-sided) gynecomastia.
Here are rough estimates for the prevalence of gynecomastia in countries where the predominant language is English:
| COUNTRY | ESTIMATED NUMBER OF AFFECTED MEN |
|---|---|
| Australia | 1,098,15 |
| United Kingdom | 3,323,752 |
| United States | 16,194,231 |
| Canada | 1,792,713 |
| New Zealand | 220,247 |
| South Africa | 2,451,202 |
The incidence of gynecomastia is greater in males with a genetic disorder affecting their sex chromosomes. For example, 1 in 650 males in Australia is born with Klinefelter syndrome, and is prone to gynecomastia. In the U.S.A., 1 in 500 to 1,000 males has an extra sex chromosome.
Ancient Egyptian statues of men with gynecomastia were unearthed by archaeologists, so we know it has always been with us. Mastectomy (breast reduction surgery for gynecomastia) was reported in 690 A.D. by Paulas and Aegina.