How does our brain respond to stress? 

At some point in our lives, we have all most likely experienced the very natural, but uncomfortable physical and emotional symptoms that are triggered when we are feeling stressed. Symptoms include: sleepless nights, feeling easily irritable or frustrated, a racing heart, the uncomfortable feeling in the pit of your stomach, or just total overwhelm when things get too much. But have you ever thought about why?

According to the APA Dictionary of Psychology, stress is defined as “The physiological or psychological response to internal or external stressors. Stress involves changes affecting nearly every system of the body, influencing how people feel and behave.”

Let’s explore what is involved in this response and understand how stress affects the functioning of our brain at a deeper level.

The brain is the critical organ in the body that processes, regulates, monitors, reacts and adapts to all types of environmental, social, psychological and emotional stressors we encounter day to day.

The acute stress response that we experience is directly controlled by the Hypothalamus Pituitary Axis (HPA) as illustrated in figure 1. The hypothalamus explicitly integrates information from the central nervous system and controls our hormonal responses.

When presented with a stressor, the Hypothalamus is activated to manage the release of a specific hormone from the pituitary gland that sits below it.1

Figure 1. ‘Hypothalamus and Pituitary’ by Casey Henley

The hormone that is released during the stress response is known as cortisol, a type of steroid hormone. The release of cortisol triggers an automatic physiological reaction that primes our body for action, whether that is fighting or fleeing from the stressor, recognised as the ‘fight or flight response’.

This mechanism in the brain is an important evolutionary adaptation designed to protect the body from danger, and in some cases can have a positive effect. However, if experienced too frequently, prolonged exposure to chronic stress is maladaptive and leads to overproduction of cortisol in your brain, which ultimately inhibits the HPA’s ability to control the effects of stress in your body.

This can initiate uncomfortable behavioural and symptomatic responses such as an increased heart rate, nausea, dizziness, racing thoughts and difficulty sleeping.

In more serious cases, exposure to chronic stress can lead to serious cardiovascular issues such as hypertension, heart attack or stroke and mental illnesses such as depression and anxiety disorders.

Understanding how stress affects the brain can help us to recognise the symptoms and manage them. The signs of stress can be easily confused with many other conditions and it’s not unusual to find that you don’t realise you’re stressed until you reach your breaking point.

An effective way to recognise signs of stress is to take some time out of your day – just five minutes will do – to ask yourself how you are feeling. By examining how you’ve felt across the day or the week as a whole, you may be able to spot pressure or emotional discomfort.

This is why our One Wellbeing app will invite you to do a regular emotional check-in. We ask app users to go into further detail about their day and how they are feeling. This self-reflective time can be the key to tackling stress before you reach a full burnout.

While stress affects all of us in some way shape or form, we always recommend you seek medical assistance if this is something you’re struggling with.

This month, we’ll be learning more about stress across our social media channels. We’ll be providing you with tips and advice to tackle and avoid stress.

Want to learn more about how stress is affecting you and your employees? Keep your eyes out for our next blog on how to effectively manage stress.



Ellie Caley

Workplace & Wellbeing Consultant, ART Health Solutions

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