Keep Calm and Carry On

Imagine you’ve just walked into a room to find a hungry looking lion, or a big snake, or perhaps a desk with your most dreaded exam paper. Despite being very different scenarios, the effect will be broadly similar. Emotionally, you will experience varying degrees of fear (from anxiety to panic), and a heightened sense of alertness (hypervigilance). Physically, your heart rate, blood pressure and breathing rate will increase, your skin will become pale and your muscles may tremble. These are all hallmarks of the fight or flight response and many are the result of a surge adrenaline. Overall, the fight or flight response prepares the body for physical activity. The response promotes carrying on, but it does not promote keeping calm.

In some people, the emotions of anxiety and panic can appear in situations where there is no obvious threat (no lion, snake or exam paper). Nevertheless, these feelings of panic are associated with identical changes in heart rate and breathing rate because the emotions trigger the same physical elements of the fight or flight response. This link between the emotion and the physical responses to fear are of interest to scientists, but it is worth asking if this link is of any practical value? Can we use it to reduce anxiety?

The answer to this question depends on whether it is possible to reverse the direction of the fight or flight response. The normal direction is emotion first, then physical, but could a physical change (heart or breathing rate) somehow drive an emotional response?

The simple answer is yes. There is evidence that the link between the emotional and the physical sides of anxiety does work in reverse. In one direction, anxiety and panic lead to increases in heart rate and breathing rate, and in the other direction, an increase in breathing or heart rate can lead to anxiety and panic. How can this knowledge help us to ‘keep calm and carry on’ rather than the more common, and less agreeable, ‘carry on in fear and panic’?

Understanding this question requires a little knowledge of the brainstem, an evolutionarily old area of our brain that sits between the spinal cord and the brain, and which controls things like breathing, blood pressure and heart rate. These control functions of the brainstem evolved together when the brain was far smaller and simpler, and has resulted in a link between the control of breathing and heart rate that does not appear to serve any useful function, but which we can use by consciously controlling how we breathe. It turns out that the brainstem provides all we need to control anxiety – to ‘keep calm’ – by controlling our breathing rate.

This link provided by the brainstem means that the act of breathing alters the activity of nerves that slow down heart rate, so that heart rate increases as we breathe in, and decreases as we breathe out. However, when the heart rate is high during exercise, or during the fight or flight response, the variation in heart rate caused by breathing is much smaller.  The effect of breathing on heart rate and blood pressure is greatest if we consciously breathe more slowly and deeply.  Deep, slow breathing has the effect of slowing average heart rate and reducing blood pressure but, more interestingly, it appears also to reduce anxiety.

Many cultures have developed strategies to promote calmness that involve deliberate control of breathing, with meditation and yoga being perhaps the most widely known. It seems possible that by consciously slowing the breathing cycle, heart rate and the concentration of adrenaline in the blood would fall. There is some experimental evidence that a fall in adrenaline would reduce feelings of anxiety. Firstly, drugs that block the action of adrenaline have been found to reduce symptoms of panic in post-traumatic stress disorder. Secondly, if  people with a history of panic disorder are given an infusion of adrenaline, it triggers their panic.

The potential for breath control to reduce blood pressure has been studied for some time. Working in the 1970’s, Herbert Benson, an American cardiologist, used the term ‘Relaxation Response’ to summarise the effect of breath control on blood pressure.

The Relaxation Response, first published in 1975 (Image credit,

Benson was studying high blood pressure and was aware that people and animals with abnormally high blood pressure tended to have abnormally high levels of adrenaline, and that treatments (drugs or surgery) that reduce adrenaline release also lower blood pressure. The relevance of this information is that, people with anxiety appear to be at greater risk of developing high blood pressure. Benson also knew about the effect of slow and deep breathing on the nerves that slow down the heart and reasoned that if he could train people to control their breathing and calm their minds, their blood pressure would be reduced. This turned out to be the case as Benson’s study demonstrated that patients could substantially lower their blood pressure using little more than a breathing exercised performed for 20 minutes, twice per day. Benson’s insight was to recognise that consciously slowing breathing (and relaxing the mind) could make use of the link between the physical and emotional responses to stress in order to reduce blood pressure and promote emotional calmness.

We tend to expect there to be a drug to fix nearly anything and so it seems unsophisticated, almost primitive, that we would not use a drug to reduce anxiety. The simple fact is that by invoking the Relaxation Response, requiring little more than deep and slow breathing, one really can damp down the physical and emotional effects of stressful situations. With luck you won’t bump into any hungry lions or big snakes, but examination papers are not going to so easy to avoid! Take control. Use the Relaxation Response and you should be able to keep calm and carry on.

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