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What is puberty?

hormone; menstruation; testes; testosterone; sperm; pituitary; ovary; grow; puberty; change; testicle; changes; gland; hypothalamus; oestrogen; progesterone; pubic; hair; pubic hair; develop; sexual; androgen; period; periods;


Puberty is when your body changes from being a child to being an adult.

Apart from the first year of your lives the most growing that you do happens during puberty. All of a sudden, most of you seem to be growing out of clothes and shoes at an alarming rate as you go into a full-on growth spurt.

pubertyDo your feet and hands seem to be in different places all the time?

Have you turned into an eating machine?

Do you get weird pains in strange places?

Do your moods change from one minute to the next?

Do your hair and skin get greasy?

Does your body seem to be doing its own thing?

Is your mind working overtime trying to deal with all the changes?

Do not panic!
Everyone goes through this stage, even your parents did! (In the distant olden days of course.)

So what is puberty?say pee-you-ber-tee)

About two years before you notice any changes, your brain starts the work that will eventually change you from a child to an adult.

pubertyTwo parts of the brain called the hypothalamus (hy-po-thal-a-mus) and the pituitary (pit-u-it-ary) gland start making a lot more of some hormones including growth hormone, LH (lute-in-ising hormone) and FSH (follicle stimulating hormone). These hormones act on other parts of your body to make the changes happen.

Both boys and girls have these hormones but they act on different parts of their bodies.

Hormones are chemicals that are made by one part of your body (a gland) to act on a different part, such as bones. For example a gland in your brain makes growth hormone, and it works by making your leg, foot and arm bones grow longer. You have many hormones that travel around in your bloodstream doing different jobs.

For boys the LH and FSH work on their testes and adrenal glands (glands next to the kidneys) to make androgens (sex hormones) such as testosterone. They also work on the testes so that they start to make sperm.
For girls these hormones work on their ovaries (where all the eggs that they will ever have, are stored since before they were born), as well as on their adrenal glands, so that they make more of the female sex hormones such as oestrogen (say east-row-jen) and progesterone (pro-jest-ter-own) as well as androgens.

Both boys and girls have some of all of these hormones but boys have more androgens and girls have more oestrogens, and the different levels of these hormones make the differences in their bodies.

It is the action of these hormones getting your body ready for adult life that we call Puberty.

When does puberty happen?

The quick answer is 'when your body is ready to change'.

For girls puberty can start anywhere between the ages of 8-13 years (and sometimes earlier or later) but often the first changes happen around 10 or 11 years.
For boys the first changes often happen a bit later than they do for girls, somewhere between 10 and 15 years. With quite a lot of boys the first changes start to happen when they are around 11 or 12 years old.

As we are all different we can go through puberty at different times and at different rates. Some people seem to go through all the changes easily and others may have a few problems.

What are the changes to your body?

Some changes are the same for both girls and boys.

Changes like:

Other body changes depend on whether you are a boy or a girl. Have a look at Puberty - boy changes, girl changes.

Emotional changes

Both boys and girls go through all sorts of emotional changes at puberty.


Sometimes I think that society is a bit unfair on boys here.

Everyone knows that girls can get emotional when they are experiencing hormonal changes and starting menstruation, but boys are also coping with hormonal changes, although usually a couple of years later than the girls, and they sometimes get forgotten.

Have a look at the topic Puberty - changes in thinking

Dr Kim and Dr Kate say:

Dr Kate and Dr Kim"Don't try to cope all on your own."

Puberty is a time of many changes. It can be a very exciting time and a very worrying time. Remember, every adult has been through puberty, and they do have some ideas about what may be worrying you. If you are worried about something then do talk to your parent, teacher or trusted adult.

Sometimes other kids are not always the right people to ask as they may not have the right information you need, or they may not have understood things properly. What about getting a book out of the school or local library?

Remember everyone goes through puberty and everyone's experience will be different, so if you are really concerned about something, do ask. If you can't get the right answers from anywhere else, or you don't feel comfortable asking those kind of questions, go and see your doctor.

If you want to read more check out the Related Topics listed under the Feedback button.

Answering your questions

Does everyone go through puberty?

  • Yes. Puberty is the normal process that kids grow through to become adults who can have children.

When are you fully developed?

  • The average age for girls to finish growing is about seventeen.
  • Boys have usually finished growing by about nineteen.
  • A person is not fully sexually mature until two or three years after reaching full adult height, but girls can have a baby, and boys can father a child even when they are not fully physically mature.

(If you have any other questions, send them in on the feedback. We can't answer them personally, but we'll include the answers in the topic if we can. You don't have to give your name.)

One good resource that answers lots of kids' questions is 'The Puberty book'* by Wendy Darvill and Kelsey Powell. Published by Hodder and Stoughton.

Crossword puzzle

Print out this crossword puzzle about puberty - instead of clues it has a 'code cracker table'

PDF document Clueless crossword puzzle


What is puberty?
Sounds like a disease.
Does your face turn purple?
Do you cough and sneeze?
Does it last a long time or just a little while?
Does everybody get it?
Do my questions make you smile?
Oh, puberty is something that everybody knows
Happens when your body grows and grows and grows!
Inside and outside your body changes, then
You've become an adult and never a child again.
(Well, not on the outside anyway!)



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We've provided this information to help you to understand important things about staying healthy and happy. However, if you feel sick or unhappy, it is important to tell your mum or dad, a teacher or another grown-up.


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