Growing Up: Puberty in Boys

How old is your son? If he is still young, do you worry about the growth changes that are still to come? Puberty is about the physical changes your son will go through. Together with the emotional side of adolescence, these changes signal childhood’s end and the beginning of adulthood.

For parents, being able to help your son deal with anxiety, uncertainty, fear, shyness, and various other experiences throughout puberty is so important. It is also good to know more about the likely physical growth changes that occur once those hormones start whizzing around your son’s body.

At what age does puberty start in boys? What is early? What is late?

Puberty in boys starts between the ages of 9 and 14, commonly around the age of 11.

In boys, starting puberty before the age of 9 is early, and early puberty is rarer in boys than girls. If your son has signs of puberty before the age of 9 (such as enlarging testicles and penis), it is a good idea to see your child’s paediatrician.

If there are no signs of puberty by the time your son is 14 (no increase in the size of the testicles, no sign of pubic hair), or if there have been changes but they have slowed (such as some pubic hair, but the penis and testicles have not grown), then you may need to rule out hormonal problems. Delayed puberty can run in families. Certain medical conditions (such as cystic fibrosis or an eating disorder) can also delay the start of puberty.

Growing taller

A boy can grow 30 centimetres or more over the space of four years, with several centimetres of growth happening in any one year. Along with growing taller, there is growth of the hands and feet, as well as distinct changes in the appearance of the face (due to facial bones growing).

This period of quick growth in boys is the time many parents remember later – shoes and clothes are rapidly outgrown, body parts don’t seem to belong together, and there can be clumsiness.

Growth is more or less complete by the age of 18. But body shape (broader shoulders, a leaner and more muscular body) and height can continue to change and grow until the age of about 20.

Growth of pubic hair, testicles, and the penis

An early sign of puberty is the appearance of a few pubic hairs at the base of the penis. Hair also appears in the armpits. Over time, hair develops on the chin, above the lips, on the arms, around the nipples, and on the chest. (Note: not everyone gets chest hair.)

It is normal for one testicle to hang lower on one side, and even for one testicle to be slightly larger than the other. However, lumps, pain, and obvious size differences are not normal and need to be looked at by a doctor.

During puberty, the penis grows in length and width, and the testicles continue to grow until final adult size is reached. Some boys reach final adult size much later than others.

Erections are normal during puberty. They may happen for no apparent reason (they do not have to be related to sexual thoughts or to physical touch), and they can happen in unexpected circumstances, e.g., at school. An erection followed by ejaculation while sleeping is called a “wet dream,” and these are very common. Note: the erections you may see in your baby boy when you are changing his nappy (diaper) are normal, and are not related to hormones or to puberty.

Breasts in boys

Boys commonly develop breasts in early puberty, and this can cause a lot of upset. Breast tissue forms in boys due to an imbalance in testosterone and oestrogen levels (boys and girls have different levels of both of these hormones).

There may be some soreness of the breasts, and they may not appear to be the same size. Fortunately, in nearly all cases, this hormonal breast development gradually settles (usually improves within one year). In some cases, the “breasts” are not hormone-related but are due to fatty development (which is more common in boys who are overweight). It is rare for breasts to remain – if they do, you should see your child’s paediatrician.

Voice and skin changes

Hormones make the the voice box (the larynx) and the vocal cords grow and develop to make the voice deepen. While this is taking place, the voice sounds odd, as if it has cracks, breaks, squeaks, and croaks. However, this process is usually over fairly quickly, and the voice settles into its new, deeper state.

Spots, pimples, whiteheads, blackheads, and pustules can affect the face, the neck, and the shoulders. Acne can be mild, but may be severe enough to have a huge impact on self-confidence, and may even require prescription medicines. If you think this may be the case, ask your paediatrician to recommend a dermatologist.

Time scale

All puberty changes are usually completed by the age of 18. It can take approximately six years to reach adult testicle size. Before the size changes that happen during puberty, the testicles remain pretty much the same size they were during toddlerhood. From the first pubic hairs appearing, it can take a good three to four years for the whole of the pubic area to fill with hair.

During puberty, boys need lots of sleep, lots of food (in the form of a balanced diet), and plenty of parental support. Reassurance that puberty changes are normal will go a long way towards maintaining self-esteem.

Is your son going through the changes of puberty right now? Let us know any tips for parents whose sons haven’t started puberty yet. Even though puberty is something that all boys go through, knowing in advance about the ups and downs and the various changes that boys experience can be a comfort to both parents and their sons.

By Dr. Jahura Hossain

Born and brought up in London, Jahura is a U.K.-qualified doctor. She has worked in hospitals, general practice, public health, prison medicine, and the pharmaceutical industry.

Illustration by BVisual.

Beth (“BVisual”) graduated from university after studying visual communication, specialising in illustration. She’s has been working as a freelance creative and undertaken projects such as the V&A Illustration Awards in London. Currently living near Lausanne, Beth has projects involving portraits and editorial illustrations under her artist’s name BVisual.

© Copyright. Jahura Hossain. 2015. All rights reserved. No part of this article may be reproduced without the express consent of the author.