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Stress | Everything You Need To Know

Updated: Apr 30, 2023

An image of a stressed man.

Stress is defined as the body’s response to perceived threats. Those threats, or stressors, could be internal – thought processes such as negative self-talk – or external – relationship problems or occupation pressure. Regardless of the cause, nearly everyone experiences it at some point in their lives.

But if stress is left to persist or just ignored, it could negatively impact your health. In this article, we will take a closer look at the many ways it impacts our health as well as the signs and symptoms.

How stress impacts health

Stress – also known colloquially as the ‘silent killer’ – adversely affects around 75% of people.¹ According to the World Health Organisation (WHO) stress has reached ‘epidemic’ proportions and costs the global economy hundreds of millions in lost productivity and medical care.

It has been estimated that ‘over 80 percent of visits to the doctor’s office in the developed world are for stress-related disorders’ (Dr Siegel, Psy.D 2014).

Contrary to common perceptions stress doesn’t merely cause irritability, mood swings, and stomach ulcers. Around 80% of all cases of depression originate from ‘stressful life events,’ (Bullmore, 2018, p.150).

This has led the WHO to predict that stress-induced mental disease will soon be the second leading cause of disabilities (Kalia, 2002).

The immune system

In addition to causing (or exacerbating) mental health disorders, the silent killer has been shown to suppress immune function.

In his book, Why Zebras Don’t Get Ulcers, Robert M. Sapolsky, who is a Stanford professor of biology and neurology and foremost researcher into the impacts of stress on health, talks about how it impairs immune function thus increasing our susceptibility to illness and disease – such as cancer.

States of chronic – or persistent – stress have been shown to inhibit digestion, reproduction, ovulation, and the general growth and repair of tissue (Sapolsky 1994).

This goes some way to account for why people suffering from chronic stress are more likely to get ill and develop disease; for their bodies, as Sapolsky colourfully puts it, ‘halts long-term, expensive building projects’ like manufacturing antibodies whose job it is to fight, amongst other things, tumour cells.

But the harm doesn’t stop there.

Mental health

If allowed to persist – which is typically called ‘chronic’ or ‘long-term’ stress – it can contribute to the decline in physical health. Researchers have linked chronic stress to some of the major modern health concerns such as type 2 diabetes, cardiovascular disease, and obesity (Harris et al., 2017; Song et al., 2019; Bullmore, 2018).

Furthermore, the silent killer can also harm the brain!

Impacts on the brain

Emerging research is showing how stress can exert a destructive influence at both a cellular and neurological level. For example, the stressed brain halts highly important ‘building projects’ such as birthing new neurons – called neurogenesis – while also impairing hippocampal function; the hippocampus ‘is a small, seahorse-shaped structure that store your conscious memories in an organized way,’ (Greenberg 2016).

The result? Over protracted periods this neurological damage can result in a weakening of neural networks leading to diminished memory recall and, in the most severe cases, early onset of cognitive decline. The brain that weathers a lot of stress wears quicker.

Few people realize that silent killer is linked to a wide range of physical illnesses some of which include:

  • Headaches

  • Infectious illness (such as influenza)

  • Cardiovascular disease

  • Diabetes

  • Asthma

  • Rheumatoid arthritis

  • Mood swings

  • Suicide ideation

(List adapted from Curtis 2000)

Two types of stress

Before we go any further, it is important to point out that not all stress is bad for us. In fact, short-duration stress, the stuff that gets us motivated or compels us to take action, can actually be beneficial.

However, long-duration stress can erode our health and increase our risk of succumbing to the diseases and conditions highlighted above.

But the difficulty lies in distinguishing the two types, knowing which is short-duration and which is chronic.

Below, the two types have been briefly outlined and explained. Familiarise yourself with the distinctions so that, during times when you feel stressed, you can run a diagnostic and determine which type it is.

Type 1: Acute or short-term stress

In a moment of absentmindedness, you step into the road without looking, a car whizzes past while honking furiously. As well as sending your heart rate through the roof this causes a cascade of other physiological responses: an adrenaline dump, heightened arousal, perhaps a sick feeling in the stomach, sweating.

But after giving yourself a good and much deserved dressing down you go about your merry way like nothing happened. After all, the crisis is now over so why dwell on it?

  • It is short-lived and the associated responses dissipate after a few minutes

  • It triggers an intense spike of physiological responses

  • Type 1 can be induced by a million and one things

Type 2: Chronic or long-term stress

For months and months your boss has been saddling you with more and more work responsibilities and you’re feeling overwhelmed and you’ve got knots in your stomach and you can’t sleep and you’re constantly anxious and worried and, and . . .

Yep, this is chronic stress and it’s the stuff that’ll make you ill and, if not treated, potentially prematurely divest you of your mortal coil.

  • It’s long-lived and can linger in the mind and body for days, weeks, months or even years.

  • Comparative to Type 1, Type 2 is somewhat ‘mild’ in intensity. And though this may seem like a positive it isn’t. Because of this characteristic, it can lurk undetected which is where it begins sabotaging your health.

  • It is triggered by a whole host of things but typically chronic stress is caused by: work (otherwise known as ‘occupation stressors’ which the WHO says ‘is the response people may have when presented with work demands and pressures that are not matched to their knowledge and abilities and which challenge their ability to cope’²), toxic relationships, money (the lack of it) and poor socioeconomic circumstances (for example, being poor, having to endure a demeaning job and living in a crappy neighbourhood).

The signs and symptoms of the silent killer

Before chronic stress can be dealt with it must first be identified. The reason why it is called the silent killer is because, unlike a physical ailment, such as the flu, or a fractured femur, which both exhibit salient symptoms, stress can bubble away under the surface undetected.

People, in the main, just aren’t adequately educated on how to identify the signs and symptoms of stress. This must change if we hope to avoid the pernicious impacts it has on our health.

Below you’ll find an extensive list of the signs and symptoms commonly associated with chronic stress:

Physical symptoms

  • headaches or dizziness

  • muscle tension or pain

  • stomach problems

  • chest pain or a faster heartbeat

  • sexual problems

Mental symptoms

  • difficulty concentrating

  • struggling to make decisions

  • feeling overwhelmed

  • constantly worrying

  • being forgetful

Behavioural symptoms

  • being irritable and snappy

  • sleeping too much or too little

  • eating too much or too little

  • avoiding certain places or people

  • drinking or smoking more

(NHS 2020)



Wow! We’ve covered quite a lot of ground in this article and you’ve done well to get this far. Let’s finish things off by answering a few frequently asked questions.

Can stress cause high blood pressure?

Surprisingly, on their websites, neither the NHS or British Heart Foundation identify stress as a cause or trigger of high blood pressure. I say this is surprising because I thought it was well understood that stress – along with salt, sugar, sedentarism, and saturated fat – causes or at least contributes to hypertension.

However, the WHO has my back. On their website, they not only identify stress as a potential cause of high blood pressure but advise the management of stress as a method of controlling high blood pressure.

So, to the question: Can stress cause high blood pressure? the answer is an inconclusive ‘perhaps’. But it would be best to err on the side of caution. By avoiding chronic stress you can reduce your susceptibility risk of the health conditions outlined above – and maybe even high blood pressure too.

Can stress cause stomach pain?

Yes, it most certainly can cause stomach pain. In fact, chronic stress has been linked to almost every conceivable stomach/gastrointestinal complaint currently named by medical science.

‘Carefully conducted studies show that major chronic stressors increase the risk of the first symptoms of IBS appearing, and worsen existing cases,’ (Sapolsky 2004).

In addition to exacerbating IBS, one of the most common and hardest to treat gastronomic complaints, stress has also been shown to increase the production of stomach acid. As well as causing indigestion (acid reflux), which is horribly uncomfortable and miserable to many millions of people, excessive stomach acid can contribute to stomach ulcers.

Stomach, or gastric, ulcers can form ‘relatively rapidly (sometimes over the course of days) in humans who are exposed to immensely stressful crises. … Such “stress ulcers” can be life-threatening in severe cases,’ (Sapolsky 2004 – Why Zebras Don’t Get Ulcers – p85).

Where to get help?

There are many excellent support groups available that offer advice and guidance on how to reduce and remove stress from your life. To save you the trouble of scouring the internet, below are links to two support groups providing a range of free services.


To Conclude

From this article, you should have gained a comprehensive understanding of the many ways stress can impact on mental and physical health.

In addition, you should now be able to spot the signs and symptoms of stress. Armed with this information you will be better equipped to identify when you have succumbed to stress.

Further reading

Why Zebras Don’t Get Ulcers by Robert M. Sapolsky

The Stress-Proof Brain by Melanie Greenberg


(As we are very interested in user experience here at Hungry4Fitness, we would be very grateful if you could take a few seconds out of your day to leave a comment. Thanks in advance!)

Blog Author

Adam Priest, former Royal Marines Commando, is a personal trainer, lecturer, boxing and Thai boxing enthusiast.





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