The “fight or flight” hormone that gives us a quick boost of extra energy to cope with danger — including the danger of low blood glucose. When blood glucose levels drop too low, the adrenal glands secrete epinephrine (also called adrenaline), causing the liver to convert stored glycogen to glucose and release it, raising blood glucose levels. Epinephrine also causes many of the symptoms associated with low blood glucose, including rapid heart rate, sweating, and shakiness. The epinephrine response spurs the liver to correct low blood glucose or at least raise blood glucose levels long enough for a person to consume carbohydrate.
Emotions such as fear or excitement also trigger the release of epinephrine and the racing heart and sweaty palms that come with it.