Home Clinical Psychology & Psychotherapy The Physiology of Anxiety and Meditation: Why It Helps 

The Physiology of Anxiety and Meditation: Why It Helps 

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Fear and anxiety are not always necessarily bad things. These evolutionary prompts, refined over millions of years of species adaptation and survival, can help us understand when we are in a dangerous or threatening situation. Listening to the signals our minds and bodies are sending us can be an important part of protecting ourselves as we navigate the various challenges of life, and in this way, anxiety serves an important purpose. 

Things get a little bit more complicated, however, when we live with an anxiety disorder. We can no longer trust that a creeping sense of dread means that our senses have identified that something is wrong, or that the experience of full-blown panic means that we need to act immediately to save ourselves from danger. It is an unfortunate reality that the series of feedback loops key to the way our body works mean that anxiety begets anxiety, and we can quickly feel trapped in a cycle we simply can’t imagine a way out of. 

It is easily assumed that anxiety is simply a psychological problem. However, the biological processes (or physiology) that govern anxiety are something that many researchers within neuroscience are examining, and it has emerged that this response is something inbuilt in both our neurology and nervous system. This is why people with anxiety don’t simply feel fear as an emotion, they feel it physically too; often suffering from shaking hands, a pounding heart, intense headaches, and digestive issues. 

Much of what is being researched is still under scrutiny, but by understanding a little more about what is happening in our brains and bodies when we feel acutely anxious, we can start to put in place self-help techniques to counteract it. When used alongside doctor-led treatment plans, practices such as meditation can help to bring our bodies back to equilibrium, and support us in our efforts to overcome the life-altering impact of anxiety disorders

What happens when we experience anxiety 

Anxiety often starts with a ‘trigger’. It may be that, watching TV, we see an advert for a cancer charity and are struck with unpleasant thoughts centred around the fear of serious illness. This fear strikes into our ‘fight or flight’ response, creating a cascade effect in our body via the amygdala (the brain’s stress centre) and wider sympathetic nervous system (SNS). You may not be able to consciously recognise that stress hormones are being pumped into your system, but you will notice the physical changes they create – such as increased heart rate, narrowing focus, and clammy skin. 

When anxiety is triggered by our conscious mind in this way, the effect is known as top-down anxiety. It may be caused by worrying about redundancy, our friends being annoyed with us or arguments we are having with a partner. However, it is also possible to experience what is known as ‘bottom-up’ anxiety. In this case, either overt or barely perceptible stimuli in our environment (such as a loud bang, or the sense that a stranger standing too close to us) will prompt our SNS to send signals to our brain telling us that something is wrong, stoking panicked and worried thoughts which fire further activity in our amygdala. 

Either way, both ‘top-down’ and ‘bottom-up’ feed into each other to create what is known as the cycle of anxiety, of which panic attacks are perhaps the most extreme manifestation. The more worried we become, the more we provoke our SNS and send our body into ‘fight or flight’ mode. From there, our SNS becomes increasingly reactive, consistently signalling to our conscious minds that there really is something to worry about – even in completely harmless situations. 

The physiological processes described above all evolved as a survival mechanism for an emergency event, where blood pumping to our muscles and extremely focused thinking helped us to fight, freeze or run away to save ourselves from danger. But this reaction appeared so far back in our evolutionary history that it simply hasn’t caught up with either our brains’ higher executive functions or our modern world. 

To illustrate this, think how a cat will shoot away in panic when you turn on the hoover, only to immediately relax and sleep soundly as soon as it’s turned off. In order to become chronically stressed, a cat has to experience a chronic threat (such as living with another aggressive cat or having an abusive owner). We humans, on the other hand, have cognitive abilities available to us that may be beneficial in untold ways, but also mean that we can fret and ruminate about dangers even when they aren’t even apparent. 

We keep ourselves up at night with esoteric and often baseless fears, and our body still reacts as if it’s experiencing genuine peril; and because our body is reacting in this way, the feedback loops inherent to our nervous system confirms to us that there really is something ‘wrong’. Unfortunately, this situation is not helped by our modern society, where a barrage of stimuli from alarm clocks to frightening news stories keep our stress levels high. 

How meditation counteracts fight or flight

It is important that anyone living with clinical anxiety talks to their doctor and/or therapist before attempting to use meditation to manage their symptoms, but evidence suggests that this is a safe, accessible and often profoundly effective self-help technique. People have been anecdotally aware of the calming effects of meditative techniques for centuries and even millennia, but it is in recent decades that a wealth of research has revealed exactly why meditation promotes a relaxation effect

While stress and anxiety will activate our SNS, meditation works with our parasympathetic nervous system (PNS) to induce a state known as rest and repair. If you think this sounds better than fight or flight, then you’d be right! In this state, stress hormones subside, our heart rate lowers, and our conscious mind relaxes. This gives our body a chance to break through the patterns which heighten anxiety and counteract chronic stress. The more we experience rest and repair, the more our body can ‘unlearn’ unfounded fear which dominates those who experience panic attacks and anxiety disorders. 

This may all sound a little fluffy, but we can see the impact on a variety of physiological indicators – from the respective levels of neurotransmitters to observable changes in brain structure. People who live with anxiety often exhibit increased levels of cortisol, a stress hormone linked with increased systemic inflammation and decreased immune function, while also demonstrating disturbances in their serotonin (often dubbed the body’s ‘feel-good’ chemical) and GABA (a neurotransmitter that reduces neuronal excitability) systems. 

Medical studies have shown that individuals who practice meditation daily had lower blood levels of stress hormones epinephrine, norepinephrine, and cortisol. Meditation also led to lower respiration rates and heart rate and better blood flow to the brain, indicating less constriction of blood vessels; which indicates why meditation can also lower high blood pressure, a problem also associated with anxiety. Perhaps most excitingly, meditation and meditative techniques such as yoga have also been associated with increased GABA and serotonin levels.

To supplement this research, a variety of studies (but perhaps most notably the work of Sara Lazar at Harvard University) has linked the practice of meditation with brain changes coherent with the theory that it downplays our stress response. Firstly, it appears that meditators experience an increase of cortical density in the prefrontal cortex – an area of the brain associated with higher thought and executive function. Secondly, it also appears to reduce the density of the amygdala – which is highly suggestive of a less reactive fear response. 

When all this evidence (and more) is taken together, we can practice meditation with confidence in the knowledge that it has a real impact on common stress markers. Clinical anxiety has its roots in dysregulation of certain neurological and physical systems which evolved to protect us, but which can in some cases be more harmful than helpful to our well-being. Meditation helps to counteract this dysregulation and promote healthy functioning, supporting wellbeing in a truly profound way.


Will Williams is a meditation expert, author and founder of the London meditation company Beeja Meditation.

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