Ah, puberty. It can be a very interesting time in a guy's life, what with all the
changes going on. In fact, it seems like every day something on your body grows bigger
or hair begins sprouting somewhere. Each day brings a new change or two, and it can
sometimes feel like it's hard to keep up.
It doesn't happen to every guy, but one of these changes can be the development
of breast tissue. It's called gynecomastia (pronounced: guy-nuh-ko-MAS-tee-uh)
and it's completely normal — and almost always temporary.
So how exactly does a guy happen to develop breast tissue?
What Is Gynecomastia?
Gynecomastia is a condition in which breast tissue forms in guys, usually due to
normal hormonal changes during puberty.
Hormones are chemicals produced by your body's glands.
In a guy, hormones produced in the testicles are responsible for the physical changes
that begin to take place during puberty — facial hair, muscle development, a
deepening of the voice, and the lengthening of the penis, for example. Guys and girls
produce both androgens (hormones that help develop and maintain male
characteristics) and estrogen (a hormone that is responsible for
most female characteristics).
Guys have mostly androgens in their systems, but they also have small amounts of
estrogen. In girls, breast growth is caused by high levels of estrogen. Normally,
when going through puberty, a guy's production of androgens increases greatly, whereas
estrogen production remains low.
However, sometimes guys produce enough estrogen during puberty that some breast
tissue develops. Breast tissue growth in guys can appear on one or both sides of the
chest, and the breast area can feel tender. This doesn't mean a guy is turning into
a girl or anything. It's just a minor change in hormones as he begins to grow into
adulthood.
Who Gets It?
About half of all guys going through puberty have some degree of gynecomastia in
one or both breasts. It's almost always temporary, and it's very unusual for the breasts
to stay developed — they will eventually flatten out completely within a few
months to a couple of years. Gynecomastia usually goes away without medical treatment.
Even though it's just a temporary change for most teens, some guys with gynecomastia
feel embarrassed or self-conscious about their appearance. Many guys find that wearing
loose-fitting shirts helps make the condition less noticeable until the breast tissue
shrinks over time.
Surgical removal of the breast tissue is an option in some cases. If a guy finds
his gynecomastia is bothering him, he can talk to a doctor about it.
Although the most common cause of gynecomastia is puberty, it can sometimes be
caused by certain diseases or side effects of some medicines. Using illegal drugs
such as anabolic steroids, marijuana, or heroin can also disrupt hormonal balance
and lead to gynecomastia.
There's also something called pseudogynecomastia (or false gynecomastia).
This has nothing to do with puberty or hormones. It's simply due to the fact that
some guys have extra fat in the chest area, making it look like they have breasts.
A doctor's exam can tell whether a guy has gynecomastia or pseudogynecomastia.
If you're concerned or have any questions about gynecomastia, talk to your doctor.
Keep in mind that temporary breast tissue growth in guys is a common part of
puberty that will usually go away on its own.
Date reviewed: October 2016