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What does stress do to the body?

A stress response is a result of disrupted homeostasis (the body’s self-regulation) caused by a

physical or psychological stimuli. This can be either a real or perceived threat, the brain and body do not differentiate. Physical stimuli can be from physical pain, heat, cold or trauma. Psychological stimuli can include fear and anxiety such as running late for work or being stuck in traffic. This results in behavioural changes that constitute a stress response. It is a complex, adaptive response in the body involving multiple systems including the nervous, endocrine and immune.

Woman looking stressed from burnout
Stress and burnout

“Fight or flight” response

Commonly, we refer to the stress response as ‘fight or flight’. This is a fast response which results in an increased secretion of noradrenaline and adrenaline (neurotransmitters/hormones that transmit nerve signals), which help decide if it's necessary to escape or attack. The rush of these hormones lead to an increased sympathetic nervous system response. Including contraction (tightening) of smooth and cardiac muscles that can allow a person to react to a strenuous activity more than normal. Physiologically you may notice an increase in blood pressure, tightening of blood vessels, increased heart rate and cardiac output, sodium retention, increased glucose levels, oxygen consumption and heat production. In addition, behavioural changes such as increased alertness, cognition, focused attention and enhanced arousal may be experienced.

The Hypothalamic-Pituitary-Axis (HPA)

The HPA axis is involved in a slower response to stress stimuli, resulting in the release of corticotropin-releasing hormone (CRH) within the hypothalamus (control centre in the brain). After binding to receptors and proteins within the body, adrenocorticotropic hormone is released into the bloodstream which triggers the secretion of glucocorticoid hormones such as cortisol, from the adrenal cortex.

Stress and the body

Stress can affect all systems within the body such as an acute stress which constricts airway, leading to shortness of breath and increased food movement in the bowel which may reduce absorption of nutrients. The sympathetic nervous system activates the adrenal glands, whereas the parasympathetic nervous system assists with recovery of the body after the stressor is gone. You may also notice increased tension in the muscles leading to tension headaches or cramping. Reproductively, long-term exposure to stress can reduce sexual desire, sperm production and maturation, pregnancy and affect menstruation.

Long-term stress

Chronic stress over a long-period of time can lead to a dysregulated response to stress, contributing to a continued secretion of stress hormones. The immune system can become weakened leading to increased susceptibility to sickness. A reduction in sleep quality and quantity is often experienced due to elevated cortisol levels. The cardiovascular system becomes dysregulated leading to increased risk of coronary artery disease, stroke and hypertension (high blood pressure). Mental health starts to suffer leading to poor concentration, irritability and frustration, and eventually fatigue, burnout, anxiety, depression and reduced tolerance to stress. Sound familiar?

What should I do?

Stress is a normal physiological response that can be helpful when we need to overcome challenges and increase short-stints of productivity, as long as we return back to homeostasis and the stress stimulus is removed and not prolonged. If you have been exposed to a chronic episode of stress and resulted in some unwanted symptoms, it is best to seek professional help from a practitioner. Of course, starting with the basics such as removing the stress (if possible), finding ways to ‘de-stress’ and recover from a stressful event such as mindfulness, meditation or gentle exercise to help return to homeostasis. Adequate nutrition and water intake is essential for our recovery from stress, which can deplete certain nutrients and exacerbate the side effects of prolonged stress. Nutrients such as Vitamin Bs, Vitamin C, Magnesium and zinc are just to name a few. Don’t forget about improving your time asleep and re-establishing a regular night time routine for sleep.

If you’re feeling the effects of long-term stress; tired, overwhelmed/burnout, mood changes and reduced tolerance to stress. Book a consultation to organise a personalised treatment plan to help you get back on track.

Reference list

  1. Chu, B., Marwaha, K., Sanvictores, T., & Ayers, D. (2022). Physiology, stress reaction. StatPearls [Internet].

  2. National Health and Medical Research Council. (2022). Nutrient Reference Values for Australia and New Zealand.


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