Because the body can't produce insulin it has to be introduced artificially, by injections.
Sufferers test the levels of glucose in their blood throughout the day. If there isn't enough they inject some insulin into their body to help convert the glucose to energy.
Children normally need to inject insulin between and two and four times a day.
Sometimes people inject too much insulin and their blood sugar level drops too low. If this happens the best thing to do is eat something sweet like chocolate or a glucose tablet.