What is The Stress Response?

“Stress is anything that makes your body work overtime.”
– Nicole Porter –

How do you define stress? Is it a demanding job, credit card bills or a family/social conflict? Maybe you’d say that stress is slow traffic, slow wifi, or kids that won’t go to bed on time. Or maybe you’re one of the growing population who says their health is stressing them out. However you define it, you’re right – because these are all legitimate stressors.

But however you define ‘stress’, it’s important to know that, if you’re a typical working adult, you’re likely putting additional stress on your mind and body without even knowing it, and you do this by repeating 10 unhealthy habits almost every single day.


What are these hidden stressors? They’re the unhealthy habits that you repeat every single day that slowly but surely add stress to the trillions of cells that make up your brain and the rest of your body. When this stress is chronic, it can, over time, contribute to common complaints like fatigue, weight gain, anxiety, cravings, bloating, poor sleep, moodiness, headaches, eczema, hormone imbalance and other imbalances or more serious disease. These are stressors like dehydration, poor diet, lack of sleep, imbalanced exercise programs, excessive screen time, a lack of stillness, improper breathing, multi-tasking, overthinking, lack of social support, negative mindset and feeling a lack of control over various situations in your life. Yes, even the way you think can impact your physical health.

Learn more: The Top 10 Unhealthy Habits Stressing Out Your Mind and Body


First of all, it’s important to understand that your body is always trying to keep you in balance. It’s always striving for routine, predictability, or a state of ‘homeostasis’. Just like you want work/life balance, your body does too.

To demonstrate this ongoing pursuit of homeostasis, stand up on one leg and try to balance. If you feel comfortable doing so, let go of anything beside you that is supporting you. Now pay attention to all of the little muscles that are working to keep you upright, stable, balanced. This is a perfect example of your body making ongoing adjustments to keep you safe. You can also add another level of difficulty by closing your eyes or pushing up to the ball of your foot. Your body is always seeking balance.

Now, you may not realize it, but your insides do the same thing, especially when you’re under stress. (You can sit down now, by the way!)  When you’re under stress, your brain and body make ongoing adjustments to keep you in balance, to keep you safe, and in some cases, to literally keep you alive. But we’ve redefined stress, right?

So when you’re dehydrated, eat too much sugar, skip meals, don’t get enough sleep, think negative thoughts, worry about a deadline, stress about credit card payments, or have to run from a lion in the wild, your incredible body immediately kicks into gear to remove you from harm. This internal response in your body requires the cells in your brain and body to work overtime. And this is why I define stress as ‘anything that makes your body work overtime’.

This reaction is known as The Stress Response (aka “fight or flight response”) and is defined as “a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival”.

Now, you might be thinking, “I understand how I’d get stressed out if I was running for my life, but I definitely don’t feel the same way if I’m dehydrated or have lost sleep!”. It’s a fair comment, but this is why you need to know that everything starts in the brain. The brain is responsible for everything you think, feel, see, do. When you move a muscle, it starts in the brain. When you decide to look at your email again before bed, it starts in the brain. When you feel thirsty, it starts in the brain. Even the act of you subconsciously inhaling and exhaling starts in the brain. The brain says, “Oh, I sense I have too little oxygen in this body. I should inhale!” or “Hmm, I sense too much oxygen in here (or not enough carbon dioxide) and I should exhale!” This is simplifying it, but it’s true.

Everything, including The Stress Response, starts in the brain.


Stress starts in the brain, in the nervous system. You (your brain) perceive that something is about to put you out of balance, to threaten you, maybe even to put your life at risk. Then immediately, your body kicks into motion with the sole focus of getting energy to your muscles and brain so that you can get away from your threat, so that you can fight or flee. 

This is what happens after the brain perceives the stressor: 

  • The brain (hypothalamus and pituitary) immediately releases hormones that tell your adrenal glands (which sit just above your kidneys) to release cortisol and adrenaline (the word adrenal is in the word adrenaline). And right here you’ve got it folks, the beginnings of hormone imbalance and an overstimulated nervous system right out of the gate!
  • Adrenaline makes the heart beat faster. A faster heart rate means increased blood flow to the brain and muscles so you can fight or flee.  Adrenaline also helps the body break down glycogen into glucose, which you can use as fuel or energy for your muscles and brain.
  • Cortisol secretion releases amino acids (from muscle), fatty acids (from adipose tissue), and glucose (from the liver) into the bloodstream so they can also be used for energy. (This theme of glucose in the blood may remind you of a common disease – Type 2 Diabetes.)
  • The brain also tells your hormone/endocrine system to secrete or release certain hormones and inhibit certain hormones, all in the effort to keep you alive and deal with the stress your body is now under.
  • As your body quickly prepares to fight or flee, a few other things happen:
    • Blood flow is redirected towards systems that can help save your life (your legs and brain) and away from systems that aren’t priority (reproduction, immunity, digestion to name a few). This is why chronic stress can result in regular colds, bloating and digestive issues, and infertility.
    • Muscle tension (so you can protect yourself from your threat)
    • Blood clotting (in case you get cut or hurt, you don’t want to die from blood loss. Clotting is a way to prevent this. Not such a great thing when it’s chronic and can lead to heart disease!)
    • Pupil dilation (so you can see your threat clearer)
    • Water conservation (you may get a dry mouth or you might feel the need to urinate more regularly)

This entire process happens in order to save your life. How incredible that your body was able to make the adjustments just to keep you alive and well. For this reason, The Stress Response, is actually a wonderful thing in that it immediately flips into gear anything and everything you need to keep you in balance. In fact, acute stress and the quickly activated stress response can help us focus, can help us finish projects, meet deadlines, and deal with short-term stress. 

But if you’re dealing with stress every single day (which most of us are since we’re dehydrated, poorly eating, not sleeping well, overexposed to screens, not to mention dealing with emotional and mental stress), it means hormones are constantly flooding your body, throwing your blood sugar out of whack, lowering your immune system, lead to hormone imbalance, adrenal fatigue, thyroid imbalance, muscle loss, weight gain, poor sleep, digestive issues, sugar cravings, deficiencies in vitamins and minerals, and ultimately leaving your body susceptible to a host of diseases.


When you keep asking your body and brain to activate The Stress Response, when you keep forcing hormones, organs and systems in your body to readjust to keep you in balance, it’s inevitable that your brain and body will get tired.  In my programs, I refer to stress as “anything that makes your body work overtime”. How would you feel if you had to work overtime, every day of the year, year after year? You’d be tired. Your brain, your cells, the systems in your body feel the same way.

So what really happens when your body is under chronic stress? This means reproductive, digestive, immune and repair functions are halted – because they are nor priorities in the moment. Having a baby, eating dinner, dealing with your runny nose and fixing a cut you have on your skin are not priorities when your life is at risk! The only things that are priority are you getting energy to your legs to run and your brain to focus.


  • cortisol (linked to increased body fat, decreased brain function, heart disease, high blood pressure)
  • adrenaline (responsible for the increased heart rate and blood pressure you may feel under stress)
  • estrogen (an imbalance can contribute to breast/ovarian cysts, PMS)
  • thyroid stimulating hormone (responsible for metabolism, weight, body temperature)
  • blood glucose and insulin (insulin must be secreted to combat the rise in blood sugar that is caused by The Stress Response being activated)
  • inflammation (inflammation can truly be linked to any disease)


  • testosterone (sex drive, muscle mass, metabolism, bone density)
  • progesterone (menstruation and fertility)
  • DHEA (dehydroepiandrosterone is an anti-aging hormone)
  • GH, growth hormone (bone, muscle, metabolism)
  • calcitonin (calcium levels, bone density)
  • cognitive function (memory, focus, mood)
  • metabolic rate (weight, muscle mass, body temperature)

Other Systems and Processes Affected:

  • Alterations in brain chemistry involving dopamine and serotonin, affecting depression, anxiety, memory, concentration
  • Compromised digestion including bloating, gas, constipation or diarrhea
  • Compromised reproduction leading to infertility in both males and females
  • Weakened immunity compromising our ability to fight anything from colds to cancer

If we, as a society, were only dealing with acute, short-term stress, and we had learned to recover from that acute stress with proper hydration and nutrition, movement, a restful and restorative sleep, and if we were going through our days being mindful, breathing properly (did you know you probably hold your breath during stress?), not overanalyzing situations, or creating our own emotional and mental stress, then it’s likely we wouldn’t have the chronic health problems that we experience every single day.

But this isn’t the case. And this is why we need to shift the way we think about stress.

The underlying goal of the NPW Private Coaching Programs, Online Courses, and Workplace Wellness Programs is to reduce stress on your cells (in your body and brain) by addressing factors like diet, hydration, sleep, exercise, negative mindset, poor breathing, excessive screen time, etc, so that ultimately the overall stress is reduced on your body systems (organs, tissues, cells). When this stress load is reduced, your body has less work to do, giving it (and you) an opportunity to function at its best.

Feel like you need some customized advice? Schedule a Private Coaching Session here.

Learn more from this Nic’s Pick: Why Zebras Don’t Get Ulcers by Robert Sapolsky

Learn more from this Nic’s Pick: The Cortisol Connection by Shawn Talbott

Learn more: Train Your Brain. Change Your Mind by Sharon Begley

By Nicole Porter
Nicole Porter is a Stress Coach and Wellness Educator helping busy, stressed out professionals mindfully overcome the Top 10 Unhealthy Habits preventing optimal health, mindset and productivity. She is also a Registered Holistic Nutritionist, Registered Nutritional Therapist, Healthy Weight Loss Coach, and Pilates Coach with a background in Mindfulness Based Stress Reduction and Behaviour Change.

Nicole Porter Wellness

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