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Each of us has a different threshold for feeling “stressed”, yet most would agree it is not a comfortable feeling. While we may think we “know” when we are stressed, this is not always the case.
How stress shows up in the body
An aroused, or stressed, state is reflected physiologically in three body systems:
Hormones
Hormonally, cortisol and adrenaline are released when you are stressed. This can contribute to higher blood pressure and higher blood sugar levels. Cortisol has also been implicated in contributing to fat deposits around the abdomen.
Immune system
Your immune system can be adversely affected by stress. A classic example is the increased frequency of viral illnesses some marathon runners experience after a race. Even “good stress” can have negative implications for the body.
While a strong link between cancers and chronic stress has not been firmly established, there is emerging evidence that chronic severe stress may affect the healing (or lack thereof) of established cancers, and possibly contribute to cancer onset in some cases.
Note: The link between chronic stress and coronary artery disease and stroke risk is more established.
Sympathetic nervous system
The sympathetic nervous system is part of your “fight or flight” response. When it is over-activated, it can contribute to high blood pressure, a higher heart rate, and reduced heart rate variability.
The impact of chronic stress
Chronic stress is linked to an increase of cholesterol-laden plaque inside the arteries (atherosclerosis) and therefore a higher risk of heart attack and stroke.
If stress can damage the body by contributing to heart attacks, strokes, and possibly other long-term illness, how can we best measure it?
Measuring stress: symptoms vs physiology
One approach is to ask people, “Do you feel stressed?” A standardised questionnaire called DASS (Depression, Anxiety, Stress Score) can be useful, but it still relies on self-report.
It can be more convincing to measure physiological arousal and its downstream effects as well. It is possible to measure the effects of stress indirectly by assessing:
Blood markers
Blood test markers can reflect inflammation and, to some extent, organ stress or damage. Some commercial models are available overseas.
Salivary cortisol
Cortisol levels can be measured in saliva, but there are practical challenges in timing, collecting, handling, and interpreting samples, so it is not especially user-friendly.
Skin conductance
Skin conductance can reflect arousal, but it requires reliable, accessible tools and careful interpretation.
Heart rate variability assessment
Heart Rate Variability (HRV) assessment is one of the most useful methods for measuring physiological stress. In simple terms, it is an ECG performed at rest over several minutes, analysed with specialised software to estimate whether your body is in a more “sympathetic” (aroused/stressed) mode or “parasympathetic” (relaxed) mode.
Why HRV can be helpful
There is extensive research on HRV and its usefulness in measuring physiological stress, as well as its predictive value in highlighting future cardiovascular risk. Testing can be performed on site and interpreted at the time.
Most importantly, if stress is elevated, we can intervene. There is good evidence that stress management strategies can improve psychological wellbeing and reduce longer-term risk factors linked to heart attack and stroke. This forms part of the preventative focus of our full body health check up.
Executive Medicine is introducing HRV assessment as part of our preventative approach. For individuals and organisations, it can be a practical way to “keep a pulse” on stress levels, identify hidden physiological strain, and support earlier intervention.
