You may have heard people talking about 'hormones'. These are substances made in one part of the body that tell other parts of the body what do to. You can think of them as chemical messengers that are carried in our bloodstream.
Growth hormone is made in a pea-sized area just below the brain, called the pituitary gland. As you may have worked out, the message that growth hormone carries around the body is very clear: GROW!
Growth hormone makes the bones in your spine and legs grow longer and stronger, so you gradually grow taller over time.
Growth hormone does loads of other good stuff too, like building muscle, breaking down fat and helping your heart to work properly.
If you are shorter than other children of your age, your doctor may give you extra growth hormone to help you grow taller. This is called growth hormone therapy. It's a bit like having rocket boosters on your space ship, so you can zoom higher!
The sooner growth hormone therapy is started the better, so that your body can grow as much as possible during childhood. Adults cannot get any taller, even with growth hormone therapy, because their bones have stopped growing.
Click here to find out more about medical conditions that growth hormone therapy may be used for.