How does Early Stress Shape Lifelong Health?
- Rebecca Ann
- Oct 13, 2025
- 4 min read
In the late 1990s, a quiet revolution reshaped our understanding of health.
The Adverse Childhood Experiences (ACE) Study, led by the CDC and Kaiser Permanente, revealed that what happens in childhood profoundly influences health outcomes decades later.
Over 17,000 adults were asked about their experiences before age 18 across ten key categories of adversity. Researchers found that the greater the number of ACEs, the higher the risk for chronic illnesses, emotional struggles, and even premature death.
The 10 ACE Categories
Abuse
1️⃣ Physical abuse
2️⃣ Emotional abuse
3️⃣ Sexual abuse
Neglect
4️⃣ Physical neglect
5️⃣ Emotional neglect
Household Challenges
6️⃣ Substance abuse in the home
7️⃣ Mental illness in the household
8️⃣ Domestic violence
9️⃣ Parental separation or divorce
🔟 Incarcerated family member
Each “yes” counts as one point. Your ACE score reflects how many of these experiences occurred in your early life.
The Long Shadow of Early Stress
The ACE Study uncovered a clear dose-response relationship: the higher the ACE score, the greater the risk of developing both mental and physical health challenges.
Those with four or more ACEs were significantly more likely to experience:
Chronic pain and fatigue
Autoimmune and inflammatory conditions
Anxiety, depression, and PTSD
Cardiovascular and metabolic disease
Hormonal and immune dysregulation
This research revealed that early adversity doesn’t just affect emotions — it can reshape the body’s biology.
The Biology of Survival
When a child grows up in a state of uncertainty, fear, or emotional neglect, their nervous system adapts to help them survive.
The HPA axis (hypothalamic–pituitary–adrenal system), which governs stress hormones, becomes overactivated.Cortisol and adrenaline remain high, preparing the body for danger.Over time, this leads to:
HPA axis dysregulation — a “wired but tired” state
Mitochondrial dysfunction — fatigue and poor energy production
Chronic inflammation — the root of many modern illnesses
Gut–brain disruption — altered vagal tone and digestive imbalance
Epigenetic changes — gene expression that favours survival over repair
These are intelligent adaptations to threat — not flaws. The body is doing its best to keep you safe.
Polyvagal Theory: The Science of Safety
Dr. Stephen Porges’ Polyvagal Theory deepens this understanding by showing how the vagus nerve — the longest cranial nerve — constantly scans for cues of safety or danger.
It explains three primary physiological states:
Ventral Vagal (Safety & Connection)
The body feels calm, grounded, open, and connected.
Heart rate and digestion are balanced; hormones are regulated.
Sympathetic (Fight or Flight)
The body senses danger.
Adrenaline surges, heart rate increases, muscles tense, focus narrows.
Dorsal Vagal (Freeze or Collapse)
The body perceives helplessness or overwhelm.
Energy drops, numbness, disconnection, or shutdown may occur.
When early stress is chronic, the body becomes stuck oscillating between fight/flight and freeze, rarely returning to ventral vagal safety.This is what we often call living in survival mode — constantly alert, even when there’s no visible threat.
My Personal Reflection
When I first encountered the ACE Study, it felt like finding a missing link between science and experience.In both my clinical work and my own life, I saw how the nervous system’s drive to survive could manifest as perfectionism, exhaustion, or difficulty resting, even in moments of calm.
For me, safety wasn’t automatic; it was something I had to relearn. Understanding polyvagal theory helped me realise that my body wasn’t malfunctioning it was loyal, in fact I had hoped all along someBODY would look after me, and it turns out my own body was doing all it could, to do, just that. Symptom's can also be interpreted as an expression of protection.
That shift — from judgment to compassion — changed how I approached healing, for myself and for others.
The Path Back to Safety
The body has extraordinary capacity to heal when it begins to feel safe again.Through the principles of neuroplasticity, we know that what was wired through survival can be rewired through consistent cues of safety.
Healing happens through both top-down (mind-based) and bottom-up (body-based) approaches:
Restoring Regulation
Breathwork and grounding: gentle, slow exhales strengthen vagal tone.
Somatic awareness: noticing sensations and allowing emotions to move through.
Safe relationships: co-regulation through trust and connection.
Functional medicine support: reducing inflammation, stabilising energy, balancing minerals and hormones.
Gentle consistency: building daily rhythms that signal predictability and safety.
Inner Child Healing: Restoring safety to your inner child
As the body learns safety, the mind naturally follows.
From ACEs to Awareness
If you explore your ACE score, do it with care and curiosity, not self-judgment. Your score isn’t your destiny — it’s a reflection of the environments your body adapted to.
Every adaptation holds intelligence. Every system can re-learn safety.
The journey from survival to safety is not linear, but every breath, every compassionate pause, and every act of self-care is a form of reprogramming.
Because when the body feels safe… it finally remembers how to heal.
References
Felitti VJ et al. Relationship of Childhood Abuse and Household Dysfunction to Many of the Leading Causes of Death in Adults. American Journal of Preventive Medicine, 1998.
Porges, S. W. (2011). The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-regulation.
McEwen, B. S. (2007). Physiology and Neurobiology of Stress and Adaptation: Central Role of the Brain. Physiological Reviews.
Anda, R. F., et al. (2006). The Enduring Effects of Abuse and Related Adverse Experiences in Childhood: A Convergence of Evidence from Neurobiology and Epidemiology. European Archives of Psychiatry and Clinical Neuroscience.
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