How Stress Affects the Body Physiologically

Take your pick, no matter how you look at it, stress is the silent killer for the body.

Today’s Teaching is from Laura Puckett:


How Stress Affects the Body:

Researchers define stress as something that disrupts your feeling of mental balance or wellbeing. Stress activates a series of hormones that ultimately bring your body and mind back into balance. 

When you experience stress, your body goes into “fight-or-flight…or freeze” mode. Your heart rate increases, breathing quickens, muscles tighten, and blood pressure rises. This keeps you alert and safe in the short term, but stress symptoms should subside and your body returns to normal after the stressful event. In other words, those stress hormones should do their job and then simmer down.

Here’s what happens. Only a small portion of the human brain (about 12%)  understand the difference between reality and non-reality (the stuff you make up in your head).  The other 88% has no idea. So when you have a stress reaction to money for example, 88% of your brain has no idea that you’re not in danger, so it turns on the fight or flight or freeze. But there’s no danger, so the hormones associated with that system are for no reason.

Chronic stress leads to elevated hormones (e.g., cortisol) and reduced neurotransmitters (i.e., serotonin and dopamine) – these changes are very similar to what occurs during a depressive episode. Therefore, it is not too surprising that long-term stress can ultimately lead to a depressive disorder. Furthermore, there is some evidence that chronic stress may actually “rewire” your brain. Specifically, research has demonstrated that animals exposed to chronic stress have less activity in their prefrontal cortex (responsible for higher-order tasks) and more activity in the primitive parts of the brain. In other words, chronic stress increases the strength of brain regions responsible for survival and handling threats, while weakening the prefrontal cortex. These are important findings, particularly for us humans, as the prefrontal cortex is responsible for planning, decision-making, problem-solving, self-control. Disruptions in these cognitive processes can have significant impacts on our daily functioning.

When we are chronically stressed out, our body keeps releasing cortisol. Cortisol is a stress hormone, can actually interrupt our brain function when it hangs around too long and:

  •  kill brain cells
  •  shrink the size of the brain
  •  influence emotional disorders
  •  impair learning long-term

The ability to imagine is the worst, ask what if, and create narratives about the consequences of our choices is what is behind a lot of the worry and stress in our lives. 

Stress can impact:

  • Sleep quality
  • Food choices – often the sugar binge

That sugar impact can crash your:

  • mood
  • increase chronic inflammation 

Researchers believe inflammation is a major driver for:

  • mood disorders 
  • depression 
  • Increase blood glucose levels, putting you at a higher risk of developing type 2 diabetes and other problems.  
  • Lower the Immune system 


Signs and symptoms vary but include:

  • low energy
  • Insomnia
  • lack of focus
  • frequent colds
  • low sex drive
  • negative self-feelings 

Sympathetic & Parasympathetic Systems

Sympathetic- Fight or Flight

Parasympathetic- Rest, Relaxation and Repair

  1. We have our kidneys with the adrenal glands on the top of them. 
  2. Cortisol and adrenaline are released when we wake up, exercise, experience stress or are running away from a bear! This function in excess is problematic (systemic stress). 
  3. When repeatedly released, we have the familiar “fight or flight” happening, where energy is supplied via glucose but insulin production is prevented. That “heart pounding out of your chest” feeling when you realize the cop just clocked you at 20 miles over the speed limit is the cortisol narrowing your arteries and the adrenaline increasing your heart rate. 
  4. Systemic stress causes the digestive system to slow down and the immune system to suppress 40-70% because 80% of your immune system lives in the gut. Our immune system is vital to staving away illness. 
  5. What happens when the guard to the castle falls asleep? The enemy sneaks in! With our digestive system “sleeping”, 2 things can happen here:

     5A. Continuous inflammation throughout the body – over and over this can lead to an autoimmune

       disorder, cancer, body pain, anxiety/ depression.

     5B. *The gut experiences dysbiosis, an imbalance of the proper gut bacteria in the small intestine       

      yielding a bacterial overgrowth. We have a direct highway of health communication between our   

      brain and our gut. They greatly affect one another. So here, we’re seeing stress (brain) affecting the

      gut….and vice versa.

  1. 95% of our seratonin (responsible for well being, sleep, mood) is produced in the gut and sent to our brain. With bacteria overgrowth, the seratonin production slows, which will end up creating more stress on our body and we’re right back where we started. Another one of those no good cycles!

Signs of Systemic Stress:

  • Sleep < 8 hours/night and/or have problems falling or staying asleep
  • Wake up more exhausted than when you went to bed
  • Get your “2nd Wind” in the evening, when you should be going to bed
  • Tire and are achy all the time
  • Suffer from frequent upper-respiratory infections
  • Work out to exhaustion and “crave” the rush
  • Live & die by coffee or other stimulants (5 Hour Energy, Monster, etc)
  • Gain fat in the middle
  • Have memory problems
  • Have anxiety, depression or “seasonal affective disorder”