Adverse Childhood Experiences (ACEs): The Backstory Behind Patient Behaviour

Two patients can have the same condition, the same treatment plan and the same team - yet respond to care in completely different ways. One engages, asks questions and works with you. The other withdraws, avoids eye contact or refuses things that seem straightforward.

At first, it can feel confusing. You start to question your communication, your approach, even your ability.

But over time, something clicks. Health is not just about what is happening now. It is shaped by what has happened before.

Adverse Childhood Experiences or ACEs, help explain that difference.

What are ACEs, really?

ACEs refer to stressful or traumatic experiences that happen during childhood, particularly those that affect safety, stability and trust. This might include things like abuse, neglect or growing up in environments where there is conflict, fear or unpredictability. They are not rare. That is the uncomfortable truth.

The original study by Felitti et al. (1998) showed that many people experience at least one ACE and a significant number experience several. What made this research so important is that it didn’t just describe experiences, it showed how those experiences follow people into adulthood.

Why this matters in practice

ACEs are not just part of someone’s past. They shape how the body develops and how a person responds to stress, relationships and healthcare environments.

Public Health England (2018) describes a clear link between ACEs and long-term health outcomes, including chronic disease, mental health conditions and patterns of healthcare use. The more adversity someone has experienced, the higher the risk. So when you meet a patient, you are not just seeing their diagnosis. You are seeing the outcome of years of lived experience, even if you cannot see the details.

The biology behind the reaction

This is where it starts to make sense.

When stress is repeated in childhood, the body adapts. The stress response system becomes more sensitive, more reactive and slower to settle. Cortisol levels can remain elevated and the brain’s threat detection system - particularly the amygdala - becomes more alert to danger. In simple terms, the system is already on edge.

So when you approach a patient with something routine, like taking blood or inserting a cannula, their response is not always based on the present moment alone. Their brain may interpret the situation as a threat before they have time to process it logically. That is why some patients react quickly, pull away, become distressed or shut down entirely. Not because they are being difficult, but because their nervous system is trying to protect them.

Seeing behaviour differently

Once you understand this, behaviour starts to look different.

• The patient who refuses care may not feel safe.
• The one who seems abrupt may feel threatened.
• The one who disengages may be overwhelmed.
• It shifts the question from:
• “Why are they like this?”

to:

• “What might have shaped this response?”

That shift is small, but it changes everything about how you approach care.

What this means for you on placement

You are not expected to uncover someone’s past or fix the effects of trauma. But you are part of how they experience care in that moment. And that matters.

Simple things like: explaining what you are doing, asking before touching, giving someone a sense of control - can reduce perceived threat. These are not extra tasks. They are part of safe, trauma informed person-centred care.

Even when things don’t go perfectly, that awareness changes how you respond.

The power of one safe interaction

There is also something important that often gets missed. ACEs increase risk, but they do not define outcomes. Research highlighted by NHS Education for Scotland (2020) shows that the presence of even one stable, supportive adult in childhood can significantly reduce the long-term impact of adversity.

That idea carries into healthcare. You may only be with a patient for a short time, but you can still be a consistent, calm, understanding and respectful presence. You may not change their history but you can influence how safe they feel in that moment.

And sometimes, that is enough to change how care is experienced.

A final thought

You will not always know a patient’s story. In most cases, you will only see a small part of it. But ACEs remind us that behaviour does not come from nowhere. People respond to what is happening now through the lens of what has happened before. And sometimes, the most important thing you can do is not change the situation, but change how safe it feels.

📚 References

• Felitti, V. J., Anda, R. F., Nordenberg, D., et al. (1998). Relationship of childhood abuse and household dysfunction to adult health outcomes.
• Public Health England (2018). Adverse Childhood Experiences (ACEs) and health outcomes.
• NHS Education for Scotland (2020). Transforming Psychological Trauma Framework.

Disclaimer:This resource is designed for educational purposes for UK student nurses and healthcare professionals. While we strive for clinical accuracy, it does not constitute medical advice. Always refer to your specific Trust’s local policies, NICE guidelines and the NMC Code in clinical practice. Clinical scenarios can change rapidly; when in doubt, escalate to your mentor or senior clinician.