Now, hypoglycemia can be very dangerous because our brain, for example, uses glucose as the main energy source. So if we don't have enough glucose inside our blood, that can basically damage our brain cells, because the brain cannot use glucose if there is no glucose inside our blood. So let's move on to the second type of abnormality known as hyperglycemia. So hyperglycemia is the opposite of hypoglycemia in the sense that hyper means we have a very high concentration of glucose inside our blood. Now, how exactly does this actually come about? How do we obtain a high concentration of glucose inside our blood?