People's bodies need energy to function, and they get some of that energy from food.
The body uses a special hormone called insulin to convert food we eat into a kind of sugar called glucose. The glucose gives us energy.
Some people's bodies either can't produce any or enough insulin. This is called diabetes.
There are two types of diabetes, type 1 which most child sufferers have, and type 2 which affects adults more.
What is it?