Adrenaline increases your heart rate, elevates your blood pressure and boosts energy supplies.
Cortisol, the primary stress hormone, increases sugars (glucose) in the bloodstream, enhances your brain's use
of glucose and increases the availability of substances that repair tissues. Cortisol also curbs functions that would be nonessential or detrimental in a fight-or-flight situation. It alters immune system responses and suppresses the digestive system, the reproductive system and growth processes.
This complex natural alarm system also communicates with regions of your brain that control mood, motivation and fear