Help docs! I'm trying to find out what causes gynecomastia in puberty?

Gynecomastia. 1/2 of males experience gynecomastia during puberty involving hormonal stimulation of tissue. Males make some estrogen and the target tissue of breast development can respond to small amounts before a males testosterone begins to dominate.It generally subsides over 6 mo to a year.Overweight kids can have a false gynecomastia. Persistence for more than 2 yrs may require surgery for cosmetic outcom.