Stress and the Brain

It’s often said that stress is bad, but this isn’t entirely true. Some stress is actually useful because it can motivate us, help us meet deadlines, or escape alarming situations. In fact, when we experience moderate stress, this is when our performance is actually at its peak.

So what happens when stress is ‘bad’? Let’s first look at what is happening inside the brain when we experience stress.

The emotional processing part of the brain, the amygdala, receives information from the eyes and ears. It then sends messages to the hypothalamus, which is akin to the brain’s central command centre. This is what will then kickstart a flood of adrenaline and cortisol, rapid breathing, a quickened heart rate, clammy hands, and so on. In other words, the typical stress response. The hypothalamus also works in conjunction with the pituitary gland and the adrenals.

The problem with chronic stress is that it keeps these three ‘switched on’ at a moderate level, ready to accelerate the full stress response when another threat appears. The constant stream of epinephrine (also known as adrenaline) surging through the body can increase blood pressure, damage arteries and blood vessels, and raise the risk of a heart attack.

And while lots of people lose their appetite during times of sudden stress thanks to adrenaline in their system, long-term stress can see you putting on weight. This is because cortisol, a hormone released by the adrenals, increases appetite.

How stress changes the brain

Ages the brain

Recent findings presented by a University of Wisconsin research team at the Alzheimer’s Association International Conference in London found that stressful events can age your brain by up to four years. These events can range from a job loss to divorce, to living in a disadvantaged area. The researchers found the decline was related to poorer memory and thinking skills.

Enlarged amygdala

This part of the brain — the one that first processes threats and emotions — has been shown in multiple studies as being heavily impacted by chronic stress. Children with anxiety and who have experienced stressful situations in early life usually have an enlarged amygdala compared to other children. However, there is good news. Meditation has been shown to shrink the amygdala, and consequently improve emotional stability and the perception and processing of stress.

Weakened immune system

Have you ever noticed that when you’re under stress, you tend to get sick more often? This is your immune system (over) reacting to an infection that it could normally fight off successfully. It isn’t clear how stress weakens the immune system but it is believed that the body can’t control the inflammatory response as efficiently during periods of chronic stress.


Many people tend to think they perform better under stress, but this isn’t entirely true. Although stress can help with motivation, it isn’t ideal for decision-making. For example, studies have shown that when confronted with a decision while feeling stressed, people tend to give more weight to the positives rather than the negatives. This might not seem problematic at first, but instead of acting conservatively and thinking the problem through, people take more risks.

As Kinesiologists, we know that stress is an inevitable part of life. Our goal is to help you manage your stress levels and get some balance back into your life.

– Tania O’Neill McGowan, O’Neill Kinesiology College Director

Visit a Kinesiologist at O’Neill Kinesiology College to get help managing stress levels and leading a more balanced life. Find a qualified Advanced Kinesiologist near you on or call us on (08) 9330 7443.

Share this Post
Stay Connected

Subscribe to Our newsletter