Stress and the Autonomic nervous system

This week’s blog is about stress and the autonomic nervous system and is based upon part of the book I am currently writing – How to Heal.

We are all hardwired with a two-part autonomic nervous system. Autonomic means that part of the nervous system that is not consciously directed and that is responsible for bodily functions such as breathing, heart beating, digestion etc. This autonomic nervous system (ANS) has two parts – the sympathetic nervous system and the parasympathetic nervous system.

The sympathetic nervous system (SNS) is responsible for the so-called fight or flight response. It acts to quickly get our bodies ready to tackle a threat by fighting or fleeing. To do this it increases our heart rate and blood pressure. It constricts our blood vessels to route blood away from unnecessary functions such as digestion and to the skin and directs it to our muscles and brain. It opens up our airways and dilates our pupils. It also makes our hairs stand on end and causes us to sweat. The SNS promotes the release of the hormones adrenaline and noradrenaline. All these actions get us ready to fight the threat or to flee (or is some cases to freeze).

The parasympathetic nervous system (PNS) on the other hand is responsible for the rest and relax/digest response. Here we wind down the stress response and recharge. The PNS decreases our heart rate and blood pressure and dilates the blood vessels. Our breathing slows and our digestion increases. Our pupils constrict and our skin gets warmer (greater blood supply). The PNS causes release of the hormone acetylcholine. All these actions enable us to rest and digest or to feed and breed.

Of course, this is an oversimplification demonstrating two ends of the spectrum. The two parts of the ANS work together to keep our bodily functions balanced. We need both systems in balance. The trouble is in Western society the SNS is often in overdrive and the PNS is in under drive. While we don’t have the physical threats such as lions and tigers we have perceived threats and emotional and mental stress that trigger the fight or flight response. This causes a continual release of adrenaline and noradrenaline, the activating hormones that keep us on edge and lead to chronic over stimulation. This can lead to increased levels of cortisol and a cascade of physical symptoms such as increased heart rate, increased breathing, digestive problems and sweating. All of these are the same as when we are in a physical threatening situation yet when it is a chronic situation with no balance from the PNS we get anxiety and physical issues.

This week I will write about decreasing our sympathetic drive and next week I will write about increasing our parasympathetic drive.

How to decrease sympathetic drive – fight or flight

To decrease the sympathetic drive we have to examine our lives and make changes. Easier said than done. We need to look at everything in our life and try to make the changes that decrease our exposure to stress. This includes exposure to stress in its various forms – physical, emotional and mental. We need to decrease this exposure as much as we can. There are some simple ways we can do this.

  • Slow down, take more time to do things

Slowing down is against our western nature but is one way to decrease our SNS drive. In particular slow down when you’re eating; don’t make it a race to finish your meal. Pay attention to the eating and savour the food. This will help you digest better as activation of the SNS causes blood to be shunted away from the gut and the digestive processes. Taking time to eat helps the digestion.

Taking life more slowly generally will help deactivate the SNS. Avoid having to rush to get places; leave more time than you need so that you don’t become stressed.

  • Don’t multitask, do one thing at a time

Doing one thing at a time naturally slows us down and lets us be more mindful of the task at hand. Trying to do more than one thing at a time will leave you feeling pressured and increase your stress.

Do one thing at a time and pay attention to what you are doing. Be mindful of the task at hand then move onto the next task. If you’re feeling stressed by all you have to do make a list and prioritise and then tackle one task at a time.

  • Do less

Our lives can just be too busy. I remember one year when my kids were younger we were having a very busy year and Christmas was approaching. The silly season loomed over me like a monster with event after event we had to attend. Or I thought we had to attend them all. And then the kids got chicken pox and we weren’t able to attend all the events. No one cared that we had missed them all and our Christmas ended up being much less stressful. After that I consciously made the decision each year to wind back the Christmas activities and spend more time at home. Even now I try to avoid all the Christmas busyness and too many parties and instead spend time with close friends and family.

Start saying no to things you don’t want to do. Try to let go of the busy life and replace it with more relaxing time. Let go of doing and spend more time just being.

  • Avoid stimulants

If you’re too busy and stressed out then avoiding stimulants will help down regulate the SNS. Caffeine, nicotine, amphetamines or other stimulants will rev up the SNS and put you into overdrive. For many of us we take stimulants to combat a lack of sleep and relaxation and to do more than we should be doing. Ease back on busyness and the need for stimulants decreases.

  • Avoid excessive exercise

While moderate exercise can switch on the PNS and tone down the SNS, excessive exercise will fire up the SNS. If you are suffering from burn out or if stress is becoming a problem and you are an over exerciser then winding back the intensity of exercise may help. For those people who are not suffering from too much stress then excessive exercise may not be a problem but it may pay to use some of the ‘rest and relax’ techniques to help balance the body.

  • Sleep more

Sleep is the time when our bodies wind down and relax and repair. Getting enough sleep is really important and if we are highly stressed it is even more crucial. 8-9 hours is optimal and being asleep between 10 pm and 2 am is best for restorative sleep.

Stay tuned for next week’s blog where I will write about increasing our parasympathetic drive.

By Dr Carol.

Published by drcarolhead

Dr. Carol Head is an General Practitioner with over 30 years experience in General Practice and Aboriginal health services. She has a keen interest in holistic medicine and combines her medical knowledge with her passion for writing. She is particularly interested in the body's ability to heal itself and has published two books: "Holistic Medicine" and "Tools for Transformation".

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