Module 1: Lesson 1
The Basic Science of Stress (10 min)

SUMMARY POINTS

> Stress is your body’s response to changes in the environment
> Your body releases adrenaline and cortisol hormones to prepare for fight or flight
> Modern stressors trigger this response a lot even for non-threats

There are tons of articles, white papers and research reports that explain the science of stress in really complicated medical terms that national spelling bee champions would have a hard time spelling.

Here, we’ll do our best to explain everything in a more casual way. This is a very simplified explanation that won’t get into complex medical and scientific details. Hopefully, you’ll gain some valuable insight from this or at the very least, a good tip or two. 

If not, you can always use this as a sleep-aid. 😉

What Is Stress And What Causes It?

Here’s a straight up simple answer. It’s when you feel like the demands and pressures of life are beyond your capabilities to handle them.

In a slightly more formal definition: Stress is your body’s hormonal and physical responses caused by changes in your environment.

These changes can be real life-threatening events, non-life threatening mental and emotional causes, physical demands, etc. just to name a few. They mostly originate from external sources, but can also be self-generated internal ones as well.

When there’s an outside threat that has the potential to hurt or kill you, your body kick-starts an automatic system to get you ready and save your ass. This system is a combination of your senses, brain, hormonal and physical networks.

Imagine this.

You’re out for a Sunday afternoon stroll in the neighborhood. As you walk around the corner, your eyes immediately spot a large ferocious dog barking with its teeth exposed. 

Its jaws look like a giant bear trap.

At this very moment, your eyes and ears (sensory inputs) have instantly sent the data to your brain.

Your brain quickly determines that this is a truly bad situation and screams at your hypothalamus, “Holy shit! We’re about to get attacked! Get the message out!”

The hypothalamus is located deep in the middle of your brain and it’s about the size of an almond. It’s in charge of keeping your body in a stable and balanced state called “homeostasis”. It’s the comfort zone.

It makes sure that everything is working smoothly and that nothing is out of whack. It regulates your body temperature, hunger, thirst, sleep, sex drive, moods, etc. It’s also the captain in relaying stress response signals to jolt the body into a totally different state.

Continuing with the example, the hypothalamus immediately relays a nerve signal down your spinal cord to your adrenal glands (located above each of your kidneys) to unleash several hormones including adrenaline, cortisol and others.

Essentially, the hypothalamus is yelling at your adrenal glands, “get those hormones into the bloodstream NOW!”

Adrenaline is what we’d call the “Red Bull” hormone. You’ve heard of the term “adrenaline rush” right? It’s what gets your body instantly into a heightened state. It does this by triggering other key parts of your body to change their status asap.

Adrenaline is now flowing throughout your body.

> Muscles are tensed for action.
> Heart rate is faster and stronger.
> Air passages open up to maximize airflow.
> Breathing pace increases.
> Blood vessels redirect more oxygenated blood to your large muscle groups.
> Fast burning glucose is rapidly injected into your major muscles.
> Pain tolerance is significantly boosted.
> Awareness and focus are amped up.

In addition to adrenaline, cortisol is also released.

It’s popularly known as the “stress hormone” but it’s more than a stress hormone. It also cooperates with the brain to regulate your moods, feelings, metabolism and blood sugar levels among other tasks.

Here in this example, it works in together with adrenaline during these threatening situations.

It also increases your heart rate, blood pressure and boosts your blood sugar levels to get fast burning glucose to your muscles. It can also re-prioritize your body functions to stop non-critical functions like digestion during crisis moments. After all, digesting your lunch is not a major priority at this moment. Getting your ass out of this dangerous dog attack is.

At this moment, this hormonal concoction of adrenaline and cortisol along with your heightened “turbo-boosted” body state is what will help you survive this dog attack.

You are ready to literally fight the dog with your bare hands or sprint to the closest tree and race up to safety like a frightened cat.

Thankfully, the raging dog was chained to a lamp post. You just never noticed the chain at the beginning.

Now that the threat is gone, your brain and hypothalamus signal to the rest of your body, “Okay, guys....we’re good. Let’s dial it back down now, go home and change our pants.” 

Your heart rate and blood pressure lowers, muscles slowly begin to relax and breathing normalizes.

Your body’s internal systems have executed the stress response or “fight or flight” perfectly. And, it did so in an instant without you having to think about it.

This is how humans survived in the wild. It’s why our stress response is designed the way it is. It was made for these types of short-term instant emergency situations.

Quick bursts of instant reaction and readiness.

However, in today’s modern world, we are exposed to many other types of stressors that set-off the same “fight or flight” stress response. Even when they’re not life threatening.

And that’s the problem - our minds can’t tell the difference between what’s really a threat or not. It just responds to all of them. So, our mind triggers our body to be in this stressed state many more times than it really needs to be.

What makes it worse is that our external stressors aren’t momentary in nature. Some of them can last much longer - days, weeks, months and years.

This short BBC video clip summarizes and reviews things quite well and introduces some tips that we'll dive into later in this course.

VIDEO: Managing Stress 
YOUTUBE CHANNEL: BBC
LENGTH: 2:23