Does the stress response change as women transition through menopause?
I have read two interesting papers (Rossi et al., 2022 and Schwarz et al., 2024) that describe how the fight, flight, freeze (sympathetic) stress response increases as women transition through menopause which have implications on health and well-being. This fits with what I am seeing clinically. Read on to find out why and what you can do about it.
Autonomic nervous system (ANS)
From moment to moment without conscious control your body is making fine adjustments to your blood pressure, pulse, temperature, saliva, digestion, muscle contraction, pupil size, bladder, bowel, sexual function etc. Amazing! The system that controls these unconscious processes is called the ANS which consists of two main parts:
'Fight, flight, freeze' system or sympathetic nervous system
This system gets a bad rap however we should be grateful as it has been developed to keep us safe and helped our species survive. If the body perceives a threat this system is activated into defence mode, bodily processes are switched towards short term survival and inflammation is increased so the individual is ready to fight, run or play dead to stay safe. This system has not been designed to be constantly activated. If the human body was a car this could be regarded as the accelerator.
'Rest & digest', 'feed & breed', 'relaxation response' or parasympathetic nervous system
When this system is activated the body feels safe so bodily processes are switched towards long term survival to enable relaxation, digestion, libido, sexual function, repair and immune function. The main nerve controlling this system is called the vagus nerve and can help decrease inflammation. If the human body was a car this could be regarded as the brake or cruise control.
The human body is complex
In truth this is a simplistic explanation of the ANS. Instead the human body is complex with both parts of the ANS functioning at the same time and the body constantly turning the dials up and down on how much sympathetic and parasympathetic response is required. Here is an example:
Autonomic nervous system | Blood pressure | Pulse (how fast the heart is beating) |
'Fight, flight, freeze' sympathetic system | Raises blood pressure | Raises heart rate |
'Relaxation response' parasympathetic system | Lowers blood pressure | Lowers heart rate |
Our body is challenged when we sit down, stand up, become hot or cold as our body needs to respond to these environmental changes to ensure blood continues to flow around the body and avoiding fainting. When the ANS is working efficiently it is able to make fine adjustments to our blood pressure and pulse to help us transition with ease through these changes. Unfortunately, in certain conditions such as (hypertension or Postural Orthostatic Tachycardia Syndrome) the ANS is not working as efficiently to negotiate changes in posture or external temperature.
Using the car analogy the human body needs to travel along the road of life with all the various curves, hills and valleys making fine adjustments on the accelerator (sympathetic system) and on the brake (parasympathetic system). If the accelerator is being heavily used it would be more difficult to negotiate the curves on the road resulting in burnout, feelings of anxiety or medical problems associated with excess sympathetic drive (hypertension, ischaemic heart disease, stroke, dementia, heart failure etc). It is possible to improve your ANS.
Cross talk between heart and brain
Rossi et al., 2022 and Schwarz et al., 2024 present recent evidence which suggests there is cross talk between the heart and brain which is complex, multifactorial, influenced by sex difference and female hormones and discuss how menopause may shift the autonomic balance towards sympathoexcitation (increased fight, flight, freeze response).
Research has highlighted the significant role of oestrogen in regulating autonomic function although the exact mechanism isn’t clear. Less is known on the impact of progesterone on ANS. Studies have shown when rats experience an abrupt loss of circulating oestrogen (due to surgical removal of the ovaries) the sympathetic nervous system is activated and parasympathetic system is reduced. Replacing oestrogen counteracted this change with improvements in blood pressure and pulse control.
How does breathing impact ANS?
Imagine how you breathe if someone scared you……breathing fast, loudly, with the upper chest and through an open mouth is more likely to activate the 'fight, flight, freeze' response. Breathing like this is detected by the area of the brain involved in fear (amygdala) which turns up the dial on the sympathetic response.
Whereas breathing slowly, gently, in and out of the nose using the diaphragm is more likely to stimulate the 'relaxation’ response. We can therefore use our breath to self-regulate between these two systems. If the breathing pattern whilst at rest and sleeping is fast, loud, with the upper chest and through an open mouth the individual can re-educate their body to breathe more slowly, gently, in and out of the nose using the diaphragm which I have seen improve sleep, stress resilience and exercise tolerance.
Schwarz et al., 2024 highlights disordered breathing (breathing inefficiently) and carbon dioxide intolerance contribute to increases in sympathetic drive during pathological conditions. I have seen a reduction in their sympathetic drive whilst supporting others to breathe more efficiently and improve their carbon dioxide tolerance.
Other ways to impact ANS
Activities which turn down the dial on the ‘fight, flight, freeze’ response and turn up the ‘relaxation’ response dial are being in nature, meditation (especially loving kindness), calm music, painting, drawing, colouring, singing, humming, chanting, gargling, cold exposure, human touch, massage, socialising, laughter, kindness and compassion.
Conclusion
It appears biologically our bodies turn up the dial on the ‘fight, flight, freeze’ sympathetic system as we transition through menopause. Knowing this information enables us to make choices:
Say no, create boundaries (physical, time, emotional or mental) delegate, ask for additional support, be kind to yourself to reduce your ‘fight, flight, freeze’ response.
Observe how you breathe whilst resting, sleeping and moving. Is your unconscious breathing pattern helping or hindering your autonomic nervous system. Click for assessment video.
Recognise your body is changing and talk to those around you explaining in order to thrive and help others you may need to make adjustments and develop a self-care regime which includes activities to turn down the sympathetic dial.
For those that would like help to breathe in a way that induces the ‘relaxation’ parasympathetic response I offer retreats, virtual group and individual breathing re-education programmes. Click to find out more
'I am already sleeping better, feel more refreshed when I wake and have way more energy during the day. I feel in control of my sympathetic nervous system now rather than the other way round (which I believe has been the driver of my autoimmune thyroid problem). I am able to recognise much sooner when my sympathetic nervous system is triggered and using the breath-work am better able to switch this off'
References
Mancia G, Grassi G. The autonomic nervous system and hypertension. Circ Res. 2014 May 23;114(11):1804-14. doi: 10.1161/CIRCRESAHA.114.302524. PMID: 24855203.
Pavlov VA, Tracey KJ. The vagus nerve and the inflammatory reflex--linking immunity and metabolism. Nat Rev Endocrinol. 2012 Dec;8(12):743-54. doi: 10.1038/nrendo.2012.189. PMID: 23169440; PMCID: PMC4082307.
Rossi A, Mikail N, Bengs S, Haider A, Treyer V, Buechel RR, Wegener S, Rauen K, Tawakol A, Bairey Merz CN, Regitz-Zagrosek V, Gebhard C. Heart-brain interactions in cardiac and brain diseases: why sex matters. Eur Heart J. 2022 Oct 14;43(39):3971-3980. doi: 10.1093/eurheartj/ehac061. PMID: 35194633; PMCID: PMC9794190.
Schwarz KG, Vicencio SC, Inestrosa NC, Villaseca P, Del Rio R. Autonomic nervous system dysfunction throughout menopausal transition: A potential mechanism underpinning cardiovascular and cognitive alterations during female ageing. J Physiol. 2024 Jan;602(2):263-280. doi: 10.1113/JP285126. Epub 2023 Dec 8. PMID: 38064358.
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