However, male estrogen levels that are too high or are out of balance with testosterone levels can cause gynecomastia. The cause of this decrease can be conditions that block the effects of or reduce testosterone or a condition that increases your estrogen level. Merck Manual Professional Version. Harrison's Principles of Internal Medicine. Our data also indicate that boys with marked idiopathic breast development have greater body mass than other boys of similar age. If a guy finds his gynecomastia is bothering him, he can talk to a doctor about it.
There's also something called pseudogynecomastia or false gynecomastia.
Evaluation of boys with marked breast development at puberty.
Papadakis MA, et al. The cause of this decrease can be conditions that block the effects of or reduce testosterone or a condition that increases your estrogen level. This has nothing to do with puberty or hormones. Mayo Foundation for Medical Education and Research; These are not the cause of breast tissue growth for young men around puberty.