Diabetes is a disorder of blood sugar levels. It occurs because insulin in the body does not work effectively. As a result, the body struggles to regulate blood sugar levels.Treatment for type 1 diabetes always involves insulin. This replaces absent insulin and keeps blood sugar levels under control.People can self-inject insulin under the skin, or, if hospitalized, a doctor might inject insulin directly into the blood. It is also available as a powder that people can breathe in. Some people prefer to use insulin pumps, which are small devices that send insulin through tubes inserted into the skin.Insulin injections vary by how quickly they act, their peak action, and how long they last. The aim is to mimic how the body would produce insulin throughout the day to promote efficient energy intake.