Just for Guys – All About Puberty
Adolescence is a time of great change in boys, both physically and
emotionally. Changes in your body are greater than at any other time in your
life. Most boys have many questions about these changes and worry about what
is normal and what to expect.
Puberty (body changes occurring during adolescence) begins first with
some enlargement of the testicles and the growth of pubic hair. This occurs
most often between the ages of 10 and 14, or occasionally a little earlier
or a little later. This onset is determined by your own biologic
“clock” that tells your body to start producing high levels of
male hormone (testosterone). Puberty usually takes two to two and a half
years to complete. Sexual maturation (growth of the testes and development
of pubic hair) occurring during puberty is closely related to physical growth
(increase in height and weight). Genital growth is divided into
stages based on physical changes. Boys have their most rapid growth in
height when they reach stage 4 of sexual development. Boys who enter puberty
earlier will grow earlier but also finish their growth at an earlier age.
Boys who enter puberty later will continue to grow until a later age and
have “catch up” growth. Neither early nor late puberty by themselves
determine what your final height will be. How much you grow during puberty
and what your final height will be depends on your own “biologic
clock” and is most influenced by the genes you received from your parents.
Growth starts in the feet and hands first, then legs and arms. This explains
why adolescents who start to grow often are clumsy and appear
FAQ (Frequently Asked Questions)
When exactly do you know you’ve started
For boys, the first sign of puberty is usually some enlargement of
the testicles. This may occur almost at the same time as the appearance of
pubic hair. You may also notice the appearance of some body odor and increased
hair on your face and under your arms. You can see these are pretty obvious
changes and you shouldn’t have any trouble recognizing when you’ve
Is there a way to kick start puberty if I feel my body isn’t
developing as fast as my friends’ bodies are? Can DHEA be used to do
this? Is it dangerous to take?
Occasionally endocrinologists or primary care physicians will recommend
several injections of male hormone (testosterone) to “jump start”
puberty in a male with a diagnosis of constitutional delay of puberty
(late-starter). This may speed things up, but doesn’t result in a taller
adult stature. There is or preparation of DHEA that is standardized for FDA
approved for use in this age group. Therefore the answer to your question
about using DHEA is no, it cannot be used. Use of any potent steroid hormone
can be dangerous and harmful.
I’m a 15-year-old boy. I’m 5’2 and only weight
90 lbs. My parents are both very tall. I have very little pubic hair and
have never had a voice crack. I’m wondering when or if I’ll hit
puberty, and if I should see a doctor about this.
At the present time, you do have a small stature. Your weight is slightly
below the fifth percentile and your height is at the 10th percentile for
your age. This means that 90-95 percent of boys your age are larger than
you. You say you have pubic hair, although very little. Are your testicles
starting to enlarge? If so, then you’re just starting puberty. Therefore
you’re a “late bloomer” or late starter, since most boys will
enter puberty by age 12. This means you still have a lot of growth potential
left. Boys have their most rapid growth when they’re almost fully sexually
developed. Although I cannot predict your adult height for certain, I think
you’re going to pass up people who are now taller and heavier than you.
And yes, all teens should have a visit with their doctor during puberty to
check on their development, so make an appointment for a physical.
Can an X-ray show if I’m fully matured? Can it show if
I can still become taller?
Yes and X-ray called a “bone age” can show if you’re
fully mature (that is, have finished growing). There are numerous growth
plates in bones (areas where growth takes place). These growth plates close
or stop growing in a very orderly fashion. And there are tables that allow
a radiologist to very accurately measure someone’s bone age or stage
of maturation. If the plates are all closed then no more growth is possible.
My penis hasn’t grown yet, but I have hair under my arms
and in my pubic area. When will my penis grow? How long should it be? Does
masturbating effect my hormones and the size of my genital
There are several things that take place in early puberty. Generally
the first thing to occur is that the testicles began to enlarge. This may
not be easily noticed when it first begins. Shortly afterwards, and sometimes
so close together it appears to be happening all at once, you’ll begin
to see pubic hair. Growth of the penis generally begins after pubic hair
has appeared. The onset of puberty is most determined by our genes and occurs
between the ages of 10-14. So that if you’ve begun developing pubic
hair, you’ll soon begin to notice your penis is also growing. When
you’re fully developed your penis will be approximately two to three
inches when soft and five to six when erect. Masturbation plays no role in
your hormone level or the size of your genitalia. Quite the opposite, when
you start producing large amounts of testosterone you’re stimulated
One of my testicles hangs down further than the other. Is this
normal? What causes it?
Yes it’s normal. The right testicle hangs lower than the left.
This is because the blood supply to the right testicle is different than
the left. The testicle is suspended by a structure called the spermatic cord.
This is like a rope or bungy cord. The spermatic cord contains the sperm
duct, nerves, arteries and veins. The right spermatic vein attaches directly
to the inferior venacava and at a level lower than the left spermatic vein
attaches to the left renal vein. Hence the left side is held higher in the
scrotum and the right side hangs lower.
I have lumps under my nipples. Sometimes these are tender. They
seem to have become larger. Are these breasts? Will they go away? What can
I do about this?
You probably have a condition called
This is some degree of temporary breast development that often occurs in
many adolescent boys (approximately 60 percent of 14 year olds). It may consist
of just small lumps under one or both nipples (often these are tender), or
it may progress to further development so that the male breast has the appearance
of small female breast. It may also involve changes in the nipple and areola
(the dark tissue surrounding the nipple). The areola may enlarge and protrude
and show some change in color. All this occurs because during puberty both
boys and girls are producing more sex hormones, estrogen and testosterone.
And in some males, their breast tissue may be temporarily more sensitive
to the effects of these hormones. (Not everyone knows that boys, as well
as girls, have breast tissue under the nipple.)
Gynecomastia is usually not a problem. It occurs most often between
the ages of 12 and 14 years and then goes away without any treatment.
Occasionally it doesn’t resolve, or the size is large enough to cause
embarrassment, and if that occurs the breast tissue can be surgically removed.
There are some medical diseases that cause gynecomastia but these are very
rare. Also drugs, especially marijuana and some prescription medications,
may cause gynecomastia. Next time you see your doctor, ask him or her to
check your development and make sure to discuss your concerns.
I’m a 12-year-old boy. Sometimes I get an erection for
no reason. Is there something wrong with me?
You can relax, you’re perfectly normal. At the time of puberty,
you begin to produce the male hormone testosterone and begin to experience
sexual arousal. This may cause spontaneous erections (erection for no reason).
Although they may be embarrassing at times, there is nothing wrong or harmful
Reprinted with permission from TeenGrowthTM.
As a reminder, this information should not be relied on as
medical advice and is not intended to replace the advice of your childs pediatrician.
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