Why Deep Breathing Really Works To Reduce Anxiety and Stress!

As someone who has lived with anxiety for the entirety of her life, I would always get the advice to “take deep breaths”. But is there a reason why all psychologists, psychiatrists and everyone else in-between keeps telling us to breathe the moment we feel anxious or stressed? 

Let’s start with some biology. Anxiety is a normal stress response to fear. According to the National Cancer Institute it is defined as “feelings of fear, dread, and uneasiness that may occur as a reaction to stress”. Anxiety affects every part of us, our mental, physical and behavioural systems, usually in preparation for an anticipated event or circumstance that we find threatening. (Chand et. al, 2022). 

Basically, anxiety is here to protect us. Often showing up as nervousness, panic, feeling as if something is wrong, our hearts beating fast, or we might feel breathless, have chest pain or even start pacing around. It’s all to get us ready to go into action.

Anxiety becomes an issue, when it affects our every day life or is prolonged. This can lead to anxiety disorders, depression and other health issues such as hypertension, increased risk of heart disease and a suppressed immune system- making us more likely to get sick. 

This article doesn’t explore anxiety, in the context of a diagnosed mental health disorder using the DSM-V guidelines, it does explore why each and everyone of us feels anxious sometimes and how and why deep breathing can help us lessen our anxiety. If you think you or someone you may know has an anxiety disorder; excessive worrying, problems with sleep, issues with concentration, irritability and other symptoms please see a doctor or mental health practitioner for further help and guidance. 

Anxiety is a normal stress response, when a threat or danger is perceived we activate a fight or flight response. This is a protective mechanism and it quite literally tells us whether to fight or to flee. This is controlled by our sympathetic nervous system. 

The sympathetic nervous system is a part of our autonomic nervous system, which is divided into the sympathetic, parasympathetic and enteric nervous systems. We are focusing on the sympathetic and parasympathetic nervous systems, which, as the names suggest, do the opposite of each other. The role of the autonomic nervous system is to regulate our involuntary physiologic processes… fancy words that mean- they control the parts of our bodily functions that we can’t consciously control- like digestion or heart rate for example. 

The sympathetic system is our fight or flight arm, it is what is activated when you need to be up and ready for action, the parasympathetic on the other hand, calms us down and brings us back to normal. 

When our stress response is activated, a message is sent to our sympathetic nervous system and chemicals adrenaline and noradrenaline are pumped out, these get us going to respond. The thing is there are only a few ways to get rid of them. Their messengers (the things that carry them around) have to be destroyed, which can take a while and is why we may still feel anxious even when the threat is gone, or the parasympathetic nervous system is activated. 

With only two ways to stop this response, it means deep breathing has to activate at least one of them- right? Deep breathing is not something we are used to and can feel uncomfortable , most of us are shallow breathers, especially those who- like myself- are conscious about making their bellies look as flat as possible! Deep breathing has many other names, abdominal breathing, belly breathing, diaphragmatic breathing, paced respiration and so on. 

Deep breathing encourages full movement of the diaphragm, that’s a layer of fibrous tissue that changes the pressure in our chest allowing air to come in or be pushed out based on its position. This also encourages full oxygen exchange, when we breathe in we exchange oxygen for carbon dioxide, and can even help slow our heart rate and bring down our blood pressure. All signs of a stress response. 

Deep breathing activates the vagus nerve, this nerve is a part of the parasympathetic nervous system, sometimes called the “rest and digest” response. So that’s it, basically, we have found a way to hack our biology. Deep breathing stimulates the parasympathetic nervous or “bring us back to normal” system when our sympathetic nervous system or flight or fight response is activated. 

Now that we know this, how can we use it?


The internet has a plethora of resources for breathing exercises, for me, simply remembering to take a few deep breaths in the moment helps me when I’m feeling stressed, anxious and even angry! It allows me to take a pause while my body is lighting up my parasympathetic nervous system so my entire self can be calmed down using biology. 

The United Kingdom’s National Health System (NHS) has a breathing exercise on their website, I’ll share it here and link it as well. 

You can do this standing, siting or laying down. Make yourself as comfortable as you can, if you have any restricting clothes on try to loosen them. 

Ensure your feet are about hip- width apart and keep your arms to your sides or on your knees, and let’s begin

Breathe in through your nose as deeply as you comfortably can, without forcing it then out through your mouth. Keep doing this gently and regularly.

Now try counting, breathe in for 5 and out again for 5.

Do this for about 5 minutes. 

If the counting bothers you or you can’t make it to 5, don’t worry about it, just breathe in and out deeply.

Some exercises have you breathe in, hold, then breath out. I do a mixture of both exercises, but I find the first one helps me when I’m in a pinch, because I can do it anywhere and feel immediate benefits, such as in social situations where I may not know anyone, or at work during an emergency!

If this helped or you’re more curious about the biology/ physiology, please check out some other resources I linked, and there are a plethora more that exist online! 

Happy breathing, 

Dr. Samantha C. Johnson

Further reading and sources:

Read more about the physiology of anxiety  

Why breathing is so effective at reducing stress- research !

NHS breathing exercise

Here’s another breathing technique

Featured Photo by Camila Quintero Franco on Unsplash

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