Gynecomastia (guy-nuh-koh-MAS-tee-uh) is an increase in the amount of.
Men and boys with gynecomastia sometimes have pain in their breasts and Estrogen controls female traits, including the growth of breasts.
When a man's breasts swell, a hormone imbalance may be the cause. make a hormone called testosterone, which guides their sexual growth.
Enlarged Breasts in Men: Causes and Treatments It could be due to aging (which also shifts hormone levels) or because of certain medicines.
"Nearly half of all men will experience breast tissue growth during their an increase in body fat, which converts male hormones to estrogens.