8 min|Dr. Maya Kuczma

The Damaging Effects of Stress On the Body

Wellness, Mind Health, Health, Gut Health, Heart Health

Why it's not 'just stress'

My doctor says "it's just stress", but it feels like there is more to it than that.

I hear this line in my office a handful of times every week. Usually, it comes from a patient with a variety of symptoms that are seemingly unconnected. Often, they have experienced these symptoms for a long time, slowly building up over a lifetime. Maybe it began with being a ‘bad sleeper’ as a kid, developing anxiety in their teens, and noticing digestive symptoms once they were in university. Their symptoms tend to worsen around exams, or deadlines, and they may have even noticed they feel worse if they go through conflict within a relationship. They have been in and out of their doctors office and told, “you’re just stressed”.

The messaging behind this statement is conflicting; we are told that stress is the cause of everything that ails us, yet simultaneously it is minimized. Can you imagine if we treated stress the same way we treated other deadly conditions? What if your doctor looked you in the eyes and told you:

“I’ve reviewed your symptoms and I have bad news. You have a serious condition, one that could kill you if we don’t manage it. You have stress.”

The effects of stress has been linked to numerous symptoms, both physical and emotional, as well as many serious, and fatal, diseases. In fact, it’s difficult to find a condition in which stress does not play a role. And yet, we’re told we’re ‘just’ stressed. Its effects are minimized and, as a result, treatment methods typically do not address the role of stress in our lives. However, stress has effects throughout the entire body.

1. The Nervous System

When we experience stress - whether it is physical or emotional - our nervous system is triggered to respond to the perceived threat. In this reaction, known as the 'fight, flight, or freeze' response, the sympathetic nervous system signals to the adrenal glands to release the stress hormones: adrenaline and cortisol. These hormones lead to a variety of changes that help us manage the threat - our pupils dilate; our heart rate, blood pressure, blood sugar increases; and our digestive system is inhibited (this is not the time to be digesting food!).

2. Cardiovascular

In response to adrenaline and cortisol, our heart rate increases and blood vessels dilate, sending more blood to our muscles in case we need to ‘fight, flight, or freeze’. This response is incredibly important when we are in a dangerous situation. However, our nervous system can’t differentiate between an animal we need to run away from and a work deadline, or even the thought of a work deadline: to our nervous system, it is all stress. And when this stress continues over an extended period of time (hours, days, months, years), atherosclerosis - the process by which arteries become clogged - accelerates.(1)

3. Musculoskeletal System

In response to stress, muscle tension increases. Acutely, this is a helpful and adaptive response; tensing our muscles is a protective response against injury and pain. However, overtime, this response leads to chronically tense muscles, contributing to a variety of pain conditions such as migraines(2), tension-type headaches(3), and temporomandibular dysfunction.(4) Job dissatisfaction, a source of chronic stress, may also play a role in pain; chronic pain prevalence was higher in men who reported job dissatisfaction.(5) Chronic stress has also been shown to exacerbate neuropathic (nerve-related) pain.(6)

4. Digestive System

During a ‘fight, flight, or freeze’ response, the sympathetic nervous system diverts blood away from the digestive system towards the heart and lungs. Our body prioritizes the threat, and responding to the threat, over ’non-essential’ functions like digestion. Acutely, this is vital. But if the stress continues, or our perception of stress continues, the digestive system is chronically deprived of adequate blood flow, leading to digestive symptoms such as constipation, diarrhea, or bloating.

In order for our digestive system to function optimally, our parasympathetic nervous system must be activated, triggering a ‘rest and digest’ response, leading to the release of saliva, enzymes, stomach acid, and bile, enabling digestion and absorption of nutrients. The parasympathetic nervous system also activates peristalsis, the movement of food from the beginning of our digestive tract to the end, resulting in a healthy bowel movement. If we are chronically stressed, our parasympathetic nervous system isn’t activated, and we cannot adequately digest and absorb the food we eat, no matter how healthy our diet is.

Research has linked digestive dysfunction to the development of depression and anxiety, via a connection known as the ‘gut-brain axis'.(7) The connection between the gut and brain appears to be multi-directional; a stressed brain (and nervous system) alters digestion, and a dysfunctional microbiome can alter mental health. These revelations are influencing the growing field of psychogastroenterology, and have lead to a best-practice update that now encourages the use of cognitive behavioral therapy and gut-directed hypnotherapy in the management of gastrointestinal conditions.(8)

5. Endocrine System

Our adrenals, the small glands located on top of our kidneys, are first-responders when it comes to stress; by way of complex communication between the hypothalamus, pituitary, and adrenals (known as the HPA axis), they are signaled to release cortisol and epinephrine, the hormones that trigger responses to stress throughout our body. Thank goodness for this response! It is an adaptive and necessary response. But what happens to our hormonal system when this response doesn’t turn-off? What happens when our bloodstream is constantly flooded with stress hormones?

Chronic stress has been shown to increase abdominal fat deposition, insulin resistance, and oxidative stress.(9) Chronic stress has been linked to decreases in the hormones DHEA-S and DHEA. (10) DHEA-S is anti-inflammatory, and low levels of this hormone have been shown to predict all-cause mortality and cardiovascular mortality(11); low levels have also been linked to autoimmune activity(12,13), and sensitivity to pain.(14) Chronic stress has been shown to impair reproduction by way of HPA axis dysregulation.(15)

In the most basic sense, our hormonal system is built to manage acute stress; when the stress becomes chronic, various hormonal responses within the HPA axis are affected in a way that cannot be maintained, and we begin to suffer from hormonal dysregulation. Hormonal dysregulation can lead to a variety of symptoms and conditions, including, but not limited to, a loss of libido, menstrual irregularities, mood changes, insomnia, and fatigue.

6. Immune System

During a stress response, the release of cortisol activates pro-inflammatory cytokines (chemicals that promote inflammation), preparing us for any injury or infection we may experience during ‘fight, flight, or freeze’.(16) When stress becomes chronic, we continue to release pro-inflammatory cytokines, setting the stage for chronic inflammation.(17) Chronic stress has also been linked to reactivation of latent viruses; this is most obvious to anyone carrying the cold sore virus (HSV) as they typically notice a breakout when they are stressed.(18) In animal models, chronic stress has been shown to promote cancer progression, suggesting that cortisol and epinephrine may contribute to tumor growth.(19,20)

Not everyone experiences stress the same way

Current research is beginning to identify differences in stress appraisal and adaptation, and looking to epigenetic changes, lifestyle choices, and childhood experiences to greater understand susceptibility to chronic stress.

The field of psychoneuroimmunology is seeking to further understand how the immune system communicates bidirectionally with the central nervous and endocrine system; discoveries within this field will likely deepen our understanding of how stress has widespread effects throughout our body, whether we feel them or not. However, our current understanding illustrates how stress has its hand in everything. It’s not ‘just’ stress that we are experiencing; if we are stressed, everything in our body functions differently.

“But I don’t feel stressed,” I often hear. Perhaps we’ve been mislabeling stress, imagining that stress must make you frantic, panicked, or upset, when in reality our experience of stress may look like a bout of diarrhea before an exam, insomnia when preparing for a deadline at work, heart palpitations when you’re rushing to a meeting, reactivation of viral symptoms following a few nights of sleep deprivation, or an inability to relax when you go on vacation; the possibilities are endless. For many of us, we are experiencing a variety of health issues that are compounded by stress. In this scenario, it’s not ‘just stress’, but it’s also not ‘only stress’.

When we look at all of the effects of stress on the body, we can see how any health concern would be impacted, and likely worsened, by stress, making the case that every health plan should include a prescription of decreased stress.

A good rule of thumb? Eliminate the stress that you can, and change the appraisal of the stress you can’t. A good doctor can work through this process with you, and help to ensure that your body becomes better at adapting to the stress that you can’t control.