What causes a decrease in blood glucose?

Answer 1

if it got too low then the body's cells wouldn't have enough energy to preform their necessary functions and would die Low blood glucose leads to slugishness, a feeling of drunkeness. As it falls lower loss of consciousness occurs. Eventually this will result in a coma and death if not reversed.

Answer 2

A decrease in blood glucose levels can be caused by factors such as too much insulin, excessive physical activity without adequate carbohydrate intake, prolonged fasting, or certain medical conditions such as hypoglycemia.

Answer 3

Having low blood sugar is a lot rarer than having high blood sugar.  Your body actually has 3-4 hormones that raise blood sugar - cortisol, glucagon, growth hormone, maybe one other - but only one hormone that lowers it - insulin.  That is because you can live for quite a while with high-ish blood sugar, but you will die pretty fast from low blood sugar.  Having low blood sugar (being hypoglycemic) typically arises nowadays from diabetics who receive too much insulin.  I guess it can also happen if someone has not been eating in a while and all of a sudden tries doing some strenuous physical activity, but this is self limiting (since the body will make you stop doing it by having you faint, then when you are unconscious, your body will get your blood sugar back up again).