From Early Stress to Adult Illness: How Childhood Trauma Shapes Adult Health

Research in psychology, neuroscience, and medicine has increasingly confirmed what many survivors have felt for a long time: the wounds of childhood do not simply disappear over time. Childhood trauma, whether through abuse, neglect, household instability, or chronic emotional stress, can leave lasting marks not only on the mind but also on the body. These effects are not imagined; they operate through clear biological and behavioural pathways that link early adversity to adult illness, primarily through three mechanisms: poor health behaviours such as smoking or overeating, chronic stress that disrupts the body’s regulatory systems, and direct biological changes that arise from prolonged exposure to early adversity.

One major pathway involves health behaviours. Individuals who experience trauma in childhood are statistically more likely to engage in coping strategies such as smoking, overeating, substance use, or physical inactivity. These behaviours often serve as attempts to soothe or numb distress, regulate emotions, or fill the void left by unmet emotional needs. Over time, however, they contribute to conditions like obesity, cardiovascular disease, and diabetes.

A second pathway involves the physiological impact of chronic stress. When a child grows up in an environment marked by fear, unpredictability, or lack of safety, the body’s stress response, i.e. the release of cortisol and adrenaline, can become overactive. This chronic activation disrupts the body’s internal balance, keeping the nervous system on high alert long after the original threat has passed. Persistent stress of this kind promotes inflammation and suppresses immune function, both of which have been linked to a wide range of illnesses, from heart disease and cancer to autoimmune disorders. In other words, the body becomes conditioned to survive rather than thrive.

The third pathway is direct biological changes, where the experiences of early adversity are literally written into the body’s systems. Research in epigenetics, which explores how behaviours and environmental factors can alter gene function without modifying the DNA sequence, indicates that persistent stress during childhood can change gene expression, impacting the functioning of the immune system, brain, and hormonal networks throughout one's life. These changes may also predispose individuals to depression, anxiety, and other mental health conditions that, in turn, increase vulnerability to physical illness. Remember, mental and physical health are not separate domains, but two expressions of the same interconnected system.

For many, the effects of unresolved trauma also surface as unexplained physical symptoms. Chronic pain, fatigue, gastrointestinal problems, and tension headaches can all be manifestations of the body’s attempt to communicate what words once could not. These somatic expressions are not “all in the head;” they reflect the body’s deeply intelligent, albeit painful, efforts to process overwhelming experiences. In such cases, healing often involves helping the body feel safe again, not just treating the physical symptom.

Understanding these pathways offers more than scientific insight; it carries profound implications for care and compassion. Recognizing that adult illness can have roots in early adversity shifts the focus from blame to understanding. It invites a more integrated approach to healing; one that addresses both the physiological and emotional effects of trauma. Through trauma-informed therapy, supportive relationships, and practices that restore regulation to the nervous system, individuals can begin to rewrite the patterns that once kept their bodies in survival mode.

While the past may reside within the body, it doesn't have to dictate the future. Through awareness, safety, and compassionate care, the body's narrative can be reshaped, focusing not on continuous harm, but on resilience, healing, and the potential for restored health.

If this is something you’ve been affected by, please leave a comment below. If there’s something important you’d like to add, please do so. I'd love to hear from you.

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Dr. Ingela Thuné-Boyle is a licensed Practitioner Health Psychologist and a Doctor in Behavioural Medicine who specializes in improving the quality of life of people struggling with long-term health problems, chronic pain and trauma. She runs a private online (telehealth) practice at www.ingelathuneboyle.com. You can find out more about her background [here], and more about her approach to therapy [here].

📩 Contact: For therapy or other enquiries, you can contact her at info@ingelathuneboyle.com

Frequently Asked Questions (FAQs)

What does a health psychologist do?

A health psychologist helps people understand and cope with the emotional and physical effects of long-term health conditions, pain, and the lasting impact of childhood trauma. These experiences often involve deep changes in identity, daily routines, relationships, and one’s sense of safety or control. The aim of health psychology is to foster emotional resilience, mind–body awareness, and a more balanced, meaningful way of living with health challenges.

Can therapy really help with the effects of childhood trauma and chronic illness?

Yes. Unresolved early trauma can affect both emotional and physical health, often contributing to stress, anxiety, pain, and illness later in life. Therapy can help you recognize these connections, calm the body’s stress response, and rebuild a sense of safety from within. Over time, this work supports greater emotional regulation, improved physical well-being, and a renewed relationship with your body.

Is online therapy effective?

Research shows that online therapy is just as effective as in-person sessions. It offers flexibility and comfort, especially for those managing fatigue, pain, or mobility challenges. Meeting online allows therapy to take place in a setting that feels safe and accessible, supporting both emotional and physical ease.

How do I know if therapy is right for me?

If you are struggling with the emotional or physical effects of stress, trauma, or chronic illness, therapy may help. A health psychologist can support you in making sense of these experiences, developing new coping tools, and finding stability, hope, and self-compassion as you heal from the long-term effects of early adversity.

Please note: Advice given in this blog is not meant to take the place of therapy or any other professional advice. The opinions and views offered by the author is not intended to treat or diagnose, nor is it intended to replace the treatment and care that you may be receiving from a licensed physician or mental health provider. The author is not responsible for the outcome or results following their information and advice on this blog.