Healthy living

Puberty – things that change for boys

During puberty, your testicles (testes or balls) start producing the male hormone testosterone.

This hormone triggers the changes in your body. Suddenly you will grow taller and begin to develop muscles. You will also find physical changes happening to your voice, your body hair and your genitals, and possibly even your breasts.

You can expect changes to your:

  • voice (gets squeaky, then deeper)
  • body hair (armpits, chest, around penis, shaving)
  • genitals (testicles, penis)
  • sexuality (erections, wet dreams)
  • breasts.

PS: If you want to know what girls go through, have a look at Puberty – things that change for girls


During puberty your Adam’s apple (larynx) gets bigger and your voice begins to ‘break’. Your vocal cords grow quickly. As it is breaking, your voice will sometimes go squeaky when you are talking, but once it has finished breaking, you will have the deeper voice of a man.

Doug, aged 14, is smaller than Donald, aged 12

Body hair

Hair will start to grow under your arms and around the pubic area. This hair will be fine and straight at first, and will become thicker and curlier as you get older. You may also find more hair growing on your legs and arms. Hair will also appear on your chin and upper lip.

When should I shave?

Hair that will appear on your face will be fine and downy at first but become more bristly as you grow older. You will probably not need to shave much at first: this will become more regular in your later teenage years.

The time when you begin to shave is a matter of choice. You might like to talk your decision over with a parent or a trusted adult before you begin. You may also like some shaving lessons from someone who has done it before! Remember to avoid sharing razors with other people.

Your genitals (sex organs)

One area of our bodies that we tend to focus much of our attention on is our genitals – heavens knows why?! – and penises certainly can develop during puberty. It is important to remember that these changes are gradual. The tallest 12 year old will not always turn out to be the tallest 21 year old, and the same is true of penises. You may find that after you have finished developing, your penis is not as big as those of some other boys. This is totally normal and there is no cause for worry: a small penis fulfils its purpose.

A tour of the genitals

The testes

During puberty, there is a change in the functioning of your testicles (testes), which is caused by your body’s production of the male hormone testosterone. This means that your testicles begin to produce sperm. Sperm are shaped like a tadpole with ‘tails’ that enable the sperm to move. Sperm are so tiny that they can only be seen under a microscope.

Testicles need to be kept cool to promote normal sperm development. This is why they hang outside the body in a sac (bag) called the scrotum. It is quite normal for one testicle (testis) to be larger or to hang lower than the other. At birth, some boys may have experienced what is called ‘undescended testicles’ where one or both testicles fail to move down into the scrotum. This is usually corrected after birth.

However, even testicles that have moved down into the scrotum will sometimes pull back into the body, for instance in cold water, or during sexual intercourse. This is quite normal. They will eventually move back into place on their own. Any concerns you have about differences in the testicles can be talked over with a doctor.

Why should I check my testicles?

Once you have reached puberty, it is a good idea to regularly check the size and shape of your testicles. A good time to do this is in the shower.

The purpose of this check is to get to know the size, shape and texture of your testicles. It is perfectly normal for one of your testicles to be bigger than the other. But if you notice any changes in your testicles, especially a lump, you must see a doctor. One of the most common cancers for men between the ages of 15 and 30 years is cancer of the testes.

The penis: how do I look after my foreskin?

The foreskin is a fold of skin which covers the tip of the penis (glans). It is very important to keep the area beneath it clean. The foreskin should be pushed back daily and the glans gently washed.

Sometimes the foreskin is removed surgically at birth. This operation is known as circumcision. Doctors rarely recommend circumcision, but it is performed by some groups as part of their cultural and religious beliefs. In your father’s and grandfathers’ generations, most boys in Australia were circumcised. Now only about 10 per cent of boys born in Australia are circumcised each year. Sometimes older boys are circumcised for medical reasons, but this is not common.

Sexual feelings

As your body changes during puberty and later in adolescence, you may notice changes in how you feel, physically and emotionally. These feelings help to prepare us for adult life, relationships, marriage, having sex and making babies.

Find out more about relationships, sex and other stuff.

Why does my penis go hard?

For boys, one physical sign of sexual feelings is the experience of having erections.

When the penis is stimulated or a boy or a man becomes sexually aroused, the penis can change and grow from being small, limp and soft to become larger, erect and hard. This is called an erection. The penis does not contain any bone and is not made of muscle. The penis becomes erect because the tissue fills with blood under pressure.

Penises vary in size and appearance. There is a wide, natural variation in the size of adult penises, but when erect, they are mostly similar in size.

A thick whitish fluid is also produced by the seminal vesicle and the prostate gland. This mixes with the sperm to form semen. At the peak of excitement – when a male ‘reaches climax’, ‘comes’ or has an orgasm – semen is pumped out of the urethra opening of the erect penis. This is called ejaculation. The milky fluid or ejaculate (come, cum) contains 200 to 500 million sperm.

During sexual excitement, but before orgasm or ejaculation, a small amount of clear fluid may be released from the penis. This clear fluid is called pre-cum but may still carry live, active sperm.

What happens to my urine when I ejaculate?

Semen passes from the testicles up through the epididymis and vas deferens before being ejaculated through the urethra - the same tube that urine passes through. But it is impossible for urine and semen to become mixed because the flow of urine is automatically stopped when your penis is erect.

What is a wet dream?

During puberty, you can become sexually excited or aroused quite easily even while sleeping. Ejaculations that happen when you are asleep are called nocturnal emissions, or ‘wet dreams’. Wet dreams are quite normal. They are your body’s way of getting rid of an internal build-up of semen.

When you wake after a wet dream, your sheets or pyjamas may feel damp and slightly sticky. Sometimes you remember the good feeling you had in the night, or you may remember nothing at all.


About one-third of boys will experience some sort of minor breast development during puberty. This is normal and is usually nothing to worry about. You may notice swelling or lumps under your nipples. Your nipples may also feel tender when clothing rubs against them. Wearing Bandaids over your nipples may help ease discomfort.

The swelling usually lasts around 4 to 6 months, but may continue for longer. See a doctor if this is worrying you.

Where to get help


Public Health

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