A big change that happens slowly
Puberty is the time when your body starts changing from a child's body into a grown-up's body.
It does not happen overnight. It usually takes a few years, step by step.
For many children it starts somewhere between 8 and 14 years old. Some start earlier and some start later.
What starts it
Your brain sends special chemical messages called hormones around your body. You can think of them as messengers carrying instructions.
These messages tell different parts of your body when it is time to start growing and changing.
Changes you might notice
You may grow taller quickly. You may sweat more, and your sweat may start to smell. Hair may start to grow under your arms and around your private parts.
Girls usually start to develop breasts, and later they begin to have periods. Boys usually notice their voice getting deeper and their testicles and penis growing.
Your feelings may change too. Some days you may feel very happy, and other days a little grumpy or shy. That is part of growing up.
You can ask questions
Puberty is normal and healthy. Every grown-up you know has been through it.
It is good to ask questions. Choose a grown-up you trust, like a parent, an older cousin, a teacher or a school nurse. You can also learn more in Puberty Lab when you are ready.