Puberty/pūhuruhurutanga is a normal part of life – it is the process of becoming an adult, and is caused by hormones produced in your body. People experience different changes in their bodies during puberty depending on their genitalia.

What is puberty?

Puberty is the time when you start to change from being a child/tamaiti to a young adult/rangatahi.

Why does puberty start?

The changes in your body during puberty are caused by hormones, which are chemicals produced in your body.

These hormones are like chemical messages that cause the testicles or the ovaries to release other hormones.

All these hormones work together to start the changes in puberty.

When does puberty start?

There is no set age when this will happen. Puberty may start when you are eight or it may not start until much later.

In people with a vagina, puberty can starts anywhere between the ages of eight and 13 years old but often the first changes happen around 10 or 11 years of age.

In people with a penis, puberty tends to start a little later – somewhere between 10 and 15 years. For many boys, the first changes start to happen when they are around 11 or 12 years old.

What are the hormones?

The main hormones during puberty are testosterone for those with a penis, and oestrogen and progesterone for those with a vagina.

People with a vagina

During puberty your ovaries get bigger and your body will start to produce two hormones – oestrogen and progesterone.

Oestrogen causes your breast to grow and helps your vagina, uterus and fallopian tubes to develop. It also makes you grow taller and also changes the way fat is stored on your body making your waist, hips and buttocks more obvious.

After puberty, oestrogen and progesterone control your menstrual cycle or period.

People with a penis

The testosterone hormone is what starts the development from child to adult.

Testosterone is the major sex hormone for people with a penis and it is produced in the testes.

Testosterone levels rise significantly during puberty. When levels are high enough, testosterone starts the production of sperm, causes the chest and shoulders to broaden and causes facial hair to grow.

What physical changes happen during puberty?

During puberty you can expect a lot of changes to your body. Your genitals will get bigger.

In people with a vagina the breasts will grow and your vagina, uterus and fallopian tubes will develop.

In people with a penis the penis and testes will get bigger. Erections will be more frequent.

Everyone will get:

• taller, heavier and stronger
• an increase in sweating
• more oily skin
• hair growing around their genitals, under their arms and on their legs and arms.

The influx of hormones during puberty can cause a range of feelings or emotions and these feelings can change often. You might get:

• sudden mood changes
• changing emotions
• an involuntary increase in sexual feelings and fantasies.

Are there changes that only happen to people with a vagina?

Their bodies increase in size and shape during puberty. Their hips become more rounded and they get a more defined waist. The vulva, vagina and nipples get bigger and the breasts begin to develop, sometimes unevenly.

Other changes include pubic hair appearing and a vaginal discharge – an increase in the mucous produced in the vagina.

They will also start menstruating or having their period during this time.

Are there changes that only happen to people with a penis?

Their shoulders and chests become broader and their muscles get bigger. They may have a temporary swelling of the breasts as their hormones sort themselves out.

Hair starts to grow on the face and sometimes the chest.

Their voices get deeper and may go up and down or sometimes sound quite croaky all in one sentence.

The penis and testicles will get bigger; they have more erections, sometimes for no reason. Testicles usually start producing sperm between 11 and 16 years –​​ at the time they start to grow pubic hair.

They start to ejaculate and/or reach orgasm when masturbating and some people will have wet dreams.

What is menstruation?

Menstruation is more commonly known as a period – it is a normal and healthy part of having a uterus.

The first period usually occurs between nine and 14 years, generally when they weigh about 41 kilos and are about 149 centimetres tall.

Periods are sometimes irregular at first, but usually settle into a pattern after a few months. If you haven't started your period by the time you are 16, it would be a good idea to talk to a nurse or doctor.

The amount of blood that is lost during your period is small (only about three tablespoons) and this will happen gradually over your period.

How often will I get my period?

Your period will last somewhere between three and seven days. Some people have short periods and others have periods that last a little longer.

The time between the start of one period and the next is called the menstrual cycle. 

The menstrual cycle usually lasts about 28 days. This means there are 28 days between the start of your last period and the start of your next period. Cycles can be longer or shorter than this.

What does it mean when I get my period?

Once you start having your period, it means you are physically able to become pregnant.

What happens to my body during the menstrual cycle?

During puberty, reproductive organs begin to develop. When people with a uterus are born, there are hundreds of thousands of eggs (ova) inside their ovaries.

When you’ve reached puberty, each month these hormones will cause an egg to start maturing and be released from the ovary. This process is called ovulation.

The egg moves along the fallopian tube towards the uterus. At the same time, the lining of the uterus becomes thick and soft with blood and tissue. This happens just in case the egg is fertilised. It would then implant itself into the lining of the uterus and grow.

Fertilisation only happens if the egg joins with a sperm. More often than not, the egg isn’t fertilised so it is just reabsorbed back into the body.

When the egg is not fertilised, the lining of the uterus is not needed so it comes away and is released through your body through your vagina.

This is what is called menstruation or a period.