When we’re exposed to a stressful event, whether it’s real or imagined, physical or psychological, the body releases waves of stress hormones such as adrenaline, noradrenaline and cortisol. They are a veritable stress tsunami, and they signal rapid changes to the entire body.
They are all good changes, perfectly designed to help us meet the challenges of stress—so long as we follow through with the next step of the cycle. We do that when we fight or flee, or more realistically in today’s world, when we Play It Out. That’s the good news. But there’s a lot of bad news about these stress hormones when we don’t hold up our end of the deal.
Adrenaline & Noradrenaline – The Good News
The first wave is comprised of adrenaline and noradrenaline and is short-term in nature. These hormones signal the body to release energy from storage sites around the body to fuel the muscles for fighting and/or fleeing.They also increase breathing, heart rate and blood pressure to deliver this energy to the muscles and away from systems of the body not related to immediate survival.
In addition, they improve short-term memory and heighten sensory awareness. We have to pay attention to and remember events that lead up to stressful situations so we can avoid them in the future. They also increase short-term immunity to deal with possible injury during the fight or flight process.
Cortisol – The Good News
The second wave of the stress tsunami consists of the release of cortisol. This is a longer acting hormone and its job is to back up the stress response for minutes and hours afterward, and to restore balance.
One of cortisol’s primary functions is to replace all the energy spent while fighting and/or fleeing. It not only makes us hungry, but hungry for energy rich foods and “restocks the shelves” by storing fat as energy on the body. We need more energy to be able to fuel the next round of the fight or flight response.
Cortisol – The Bad News
Unfortunately cortisol has no idea whether we actually had an opportunity to fight and/or flee. In today’s environments, we were probably trapped behind a desk or steering wheel, and didn’t have a chance to Play It Out.
Cortisol wants to get energy back into the body in the most efficient way possible. The foods highest in calories of energy are fat and sugar. Cortisol is the reason we reach for ice cream, chips, fries or chocolate when we’re stressed.
Cortisol suppresses the long-term immune system in order to shunt resources for increasing short-term immunity and immediate injury. Elevated cortisol also stimulates wakefulness and leads to sleep problems and insomnia.
Cortisol – The Ugly News
When cortisol stores fat on the body, it does it in two very specific places. First, it deposits it on our blood vessel walls. It also stores it around our midsections – what I call our “fight-or-flight fuel allocation stations”. The combination of this fat stored deep within the midsection and our blood vessels is very dangerous, as it raises the risk of heart disease, type 2 diabetes, and death.
Chemicals like cortisol also shrink and change the physical structure of our brains. These influences and changes can have significant consequences on the way we interact with coworkers and clients, what decisions we make, whether we can accomplish long-term goals, and our ability to deal with daily challenges.
 McEwen, B. (1998) Protective and Damaging Effects of Stress Mediators. New England Journal of Medicine. 338(3). 171-179.
 Richards, Dave. (2013). Human Physiology. Oxford University Press. 289.
 McEwen, B., Winfield, J. (2002). The Concept of Allostatis in Biology and Biomedicine. Hormones and Behavior. 43. 2-15.