The harmful impacts of chronic stress

Chronic stress starts it all.

We are wired for survival. We will do more to avoid pain than we will ever do to have pleasure. It has to be this way for all animals. Otherwise, a species would die out. And it is via the nervous system that so much information is conveyed throughout the body: if signals are sent that indicate that your life is in danger, the body has no choice but to respond accordingly.

This means that in modern times many people spend all day, most days, on red alert, and this can impact on many body systems and parts, including:

  • the fuel your body believes is “safe” and appropriate to use in that moment
  • mood fluctuations
  • how your clothes fit you
  • the quality of your sleep
  • your digestion, and whether your tummy is comfortable or is regularly bloated
  • your blood pressure
  • your eyesight
  • blood glucose regulation
  • hunger signals
  • satiety signals
  • food cravings
  • regular energy crashes

Here’s what you need to know about the nervous system, and to help you get clear about some lifestyle choices you might like to make. This will help you signal to your body that it is “safe”.


Everything in our internal and external environments — including the food we eat, the exercise we do (or don’t do) and the thoughts we think — influences our nervous system. 

To understand this, we need to explore how the autonomic nervous system (ANS) works. The autonomic nervous system “runs” our body behind the scenes and is not under our conscious control. It regulates our heart rate, respiration rate, temperature control, and immune and hormonal systems while we carry on with life. Don’t you think it is truly miraculous that if you cut yourself the wound just heals? Don’t you think it is amazing that you swallow food and your digestive system extracts the nutrients to nourish you so you can stay alive? To say that the human body is extraordinary is an understatement!

There are three parts to the autonomic nervous system. They are the sympathetic nervous system (SNS), the parasympathetic nervous system (PNS) and the enteric nervous system (ENS). Here, I will focus on the SNS, the “fight-or-flight” system, and the PNS, the “rest and repair” system, and their interaction.

In general, the SNS and the PNS have opposite functions. When the nervous system perceives that we are under “threat” — which in modern times can be due to caffeine consumption and/or our perception of pressure and urgency — the SNS raises our heart rate, increases our respiratory rate, releases stress hormones (adrenalin and cortisol) and shunts blood away from the digestive tract to the muscles so that we can run away from, or fight, whatever is threatening us. If organ systems in the body are unhealthy, and therefore stressed themselves, or if we are mentally or emotionally stressed, that increases the sympathetic load as well.

The SNS by its very nature is catabolic, meaning that it breaks down muscle tissue due to the increased amounts of secreted cortisol. High-intensity exercise is also sympathetic in nature; the heart rate goes up, as do respiration and body temperature, and cortisol is released into the blood. And, when in excess, cortisol increases body fat, amongst other things. Once the “threat” is dealt with (is it ever dealt with in the modern world?), the PNS slows our heart rate and respiration, and it brings the blood back to the digestive tract so that we can digest our food. It also works on repairing any tissues that have been damaged in our “battle”, and allows libido to be restored (your survival instinct can’t have you thinking about reproduction when your body believes that your life is being threatened).

The PNS is able to do its wonderful work overnight, provided we go to bed early enough, because cortisol naturally starts to rise around 2am. Anxiety is so incredibly common today, often as a result of relationship challenges, financial stress, a poor diet and its consequences, worries about health or weight or whether you have upset someone, or simply the juggling act of life, worrying you might “let someone down”. Yet, a person may be in sympathetic overload and still not even mention feeling anxious.

Reducing the sympathetic load is essential to great health and energy, if the SNS is dominant. Movement is still important, but it is best approached from a different angle and with a different attitude. Far more effective exercise for SNS-dominant people are breath-focused restorative practices — exercise types such as t’ai chi, qi gong, yoga and Stillness Through Movement. These types of exercise significantly assist in increasing PNS activity via the breath, which helps balance the ANS.

As you now know, adrenalin communicates to every cell of your body that your life is in danger and prepares you to fight or flee. However, you may be making adrenalin simply because you have to make a phone call that you would rather not make, or perhaps because you have gulped down three cups of coffee already today. Or maybe your dad yelled at you a lot when you were a child, and so, even though you know now that your dad yelled a lot because that was how he communicated and coped with how stressed he felt (rather than it being about his lack of love for you), now when a male in your life raises his voice in your vicinity, you instinctively go into the “flight-or-fight” response. The majority of stress for most people in the Western world today is psychological rather than physical, and it can be constant and relentless.

I believe that one of the most enormous health challenges of modern times is that the body can constantly be on the receiving end of the “fight-or-flight” messages. There are so many factors, internal and external to us, which drive this response within us that we have to begin to choose actively not to go there, not to get caught up in the rush. And to take steps in our daily lives to allow our nervous system to have some balance. 

In a nutshell...

You want your body to move easily between SNS activation and PNS activation, not be “stuck” with the SNS activated all of the time. To do this, you need to decrease SNS stimulation by:

  • exploring how caffeine affects you — you may need to reduce your intake or take a break from it

  • explore your perception of pressure and urgency and save it for when you really need it; for example, if you have to suddenly slam your brakes on while driving — not going through your email inbox.

  • You also want to actively activate the PNS. The only way science currently knows does this is by how you breathe, specifically by extending the length of your exhalation. That is partly why a breath-focused practice can be highly beneficial. These include:

    • yoga

    • restorative yoga

    • meditation

    • Or simply schedule time in your day, every hour on the hour, for example, to become breath-aware. Drop back down into belly-breathing if you find yourself chest-breathing

Signs your nervous system needs support include:

  • you feel stressed regularly, and feel that you are on red alert

  • you are a worrier or a drama queen (or king)

  • you feel anxious easily

  • you startle (jump) easily

  • you regularly don’t sleep well

  • you struggle to say “no”

  • you laugh less than you used to

  • you feel like everything is urgent

  • you feel like there aren’t enough hours in the day.

  • no matter how well you count calories and exercise, you struggle to lose weight (I’m not suggesting you count calories, but rather that you see this as a sign that stress may need to be addressed)

  • you crave sugars and/or starches (carbohydrates)

  • you love coffee, energy drinks — anything that contains caffeine — although sometimes you notice they make your heart race

  • you don’t wake up feeling restored or with good energy

  • if you don’t go to sleep by 10pm, you get a second wind and end up staying awake until at least 1am

  • you regularly feel tired but wired

  • your breathing tends to be shallow and quite fast

  • you experience “air hunger” (and other causes for this have been ruled out)

Ideas to help you better support your nervous system:

When you understand how your nervous system works, then you start to see what it needs, and I hope the following solutions will help you put that information to good use.

  • embrace a restorative practice

  • commit to a regular practice of diaphragmatic breathing

  • instead of focusing on eating less sugar, focus on eating more dietary fats from whole foods and/or green vegetables

  • decrease or omit caffeine for four weeks (or two menstrual cycles if you experience PMT and/or period pain), and if you then feel much calmer, keep off the coffee, or switch from coffee to green tea, so that you consume smaller amounts of caffeine buffered by the effects of theanine in the green tea

  • explore your perception of pressure and urgency. Have you made what you have to do each day full of pressure and urgency? Or is it a busy life, full of opportunity that is so ridiculously privileged because all of your basic needs are met? Of course there is real pressure and real urgency in this world, but save that perception for when you really need it, not for your everyday existence.

We proudly include this blog post as an excerpt from the book, Dr Libby Weaver. “Women's Wellness Wisdom.” do to her unmatched expertise and simplicity in explaining complex ideas.

Kerry is the founder of reset brain + body, located in Plymouth, where traditional therapy is elevated through the integration of psychology, yoga and mindfulness. After nearly a decade in corporate human resources in Chicago, Kerry left the field to better help her busy and stressed peers handle life inside and outside of the workplace. Kerry can be found teaching meditation and yoga classes and seeing clients for psychotherapy and yoga therapy at reset brain + bodyWhen she's not at reset brain + body, Kerry can be found spending time exploring her new hometown of Plymouth with her husband, baby boy and dog. Connect with reset brain + body on Instagram & Facebook, check out the class schedule, or contact us to book an appointment