Type 1 and type 2 diabetes are characterized by increased blood glucose levels. They affect almost half a billion people around the globe, and this number is projected to rise as we reach the middle of the century. In most individuals, blood glucose levels are kept within a healthy range by a hormone called insulin, which is secreted by the pancreas, but this fine-tuned regulation can go wrong in type 1 and type 2 diabetes. In this animation, we lay out our current understanding of these diseases and explore active areas of research that aim to restore the body’s blood glucose control.