How Trauma Shows Up in the Body: An Evidence-Based Explanation
By Jamie Gahagan, MACP
Many people who have experienced trauma notice physical symptoms long after the event is over, such as chronic tension, fatigue, stomach issues, pain, or feeling constantly “on edge.”
This often leads to an important and sometimes confusing question: How can something psychological show up in the body?
As a trauma-focused psychotherapist who uses evidence-based treatments, I want to clarify what we do know from research, and gently correct some common misconceptions about how trauma affects the body.
Trauma Is a Whole-Body Experience
Trauma is not just a memory or a thought. It is a physiological survival response.
When a person experiences trauma, the brain and body work together to keep them alive. This involves:
The autonomic nervous system
Stress hormones like cortisol and adrenaline
Changes in attention, perception, and pain processing
These are signs of a nervous system doing exactly what it was designed to do in the face of threat.
The Nervous System and Trauma
During a traumatic event, the body may enter fight, flight, freeze, or fawn. Research shows that trauma can lead to lasting changes in how the nervous system responds to perceived danger, especially when the trauma is repeated or overwhelming.
After trauma, the nervous system may remain on high alert, even when the danger has passed. This can show up as:
Feeling constantly tense or jumpy
Trouble relaxing or sleeping
Strong reactions to reminders of the trauma
Difficulty returning to a calm baseline
This is not something that happens consciously, and actually reflects how the brain has learned to prioritize survival.
Common Ways Trauma Can Show Up in the Body
While everyone’s experience is different, trauma is commonly associated with physical symptoms such as:
1. Muscle Tension and Pain
Chronic muscle tightness, headaches, jaw clenching, neck or back pain can develop when the body remains braced for danger.
2. Gastrointestinal Symptoms
The gut and brain are closely connected. Trauma is linked to issues such as nausea, IBS symptoms, appetite changes, or stomach pain.
3. Fatigue and Low Energy
Living in a prolonged state of stress is exhausting. Many trauma survivors describe feeling “burnt out,” heavy, or depleted.
4. Increased Sensitivity to Sensations
People may notice heightened sensitivity to sound, touch, light, or internal sensations like heart rate or breathing.
5. Changes in Pain Perception
Trauma can affect how the brain processes pain, sometimes leading to chronic pain conditions without clear medical causes.
Importantly, these symptoms are very real, and they are not “all in your head.”
What the Research Actually Says
There is strong evidence that trauma affects:
The amygdala (threat detection)
The hippocampus (memory processing)
The prefrontal cortex (regulation and decision-making)
The stress response system (HPA axis)
These brain-body systems influence heart rate, digestion, muscle tension, immune functioning, and sleep. This is why trauma can feel so physical.
At the same time, it’s important to be cautious of claims that trauma is “stored” in specific organs or tissues in a literal way. The evidence supports functional changes in nervous system regulation, not trauma being trapped in the body like a toxin.
Why Triggers Feel Physical
Trauma triggers are not just emotional, they are also physiological.
When the brain detects something that resembles past danger, it can activate the same bodily responses that occurred during the trauma, even if the person knows they are safe.
This can include:
Racing heart
Shallow breathing
Sudden nausea
Dizziness or dissociation
An urge to escape or shut down
This happens faster than conscious thought, which is why triggers can feel so overwhelming and confusing in the moment.
Can Trauma Be Healed at the Body Level?
Yes, but not by bypassing the mind.
Research shows that evidence-based trauma therapies help regulate the nervous system by changing how the brain processes traumatic memories and beliefs.
Therapies with strong evidence include (but are not limited to):
Prolonged Exposure Therapy (PE)
Cognitive Processing Therapy (CPT)
Trauma-focused Acceptance and Commitment Therapy (ACT)
As traumatic memories become less threatening, the nervous system no longer needs to stay on high alert. Over time, many people notice physical symptoms decrease as well.
This is why trauma therapy is not about “releasing trauma from the body”, and it’s about helping the brain and nervous system learn that the danger is over.
When to Seek Support
If you notice ongoing physical symptoms alongside trauma history, especially if medical causes have been ruled out, working with a trauma-informed, evidence-based therapist can help.
Healing is possible. The body is not broken, it’s in survival mode!
Final Thoughts
Trauma shows up in the body because trauma happens to the whole system: brain, nervous system, and physiology working together.
Understanding this can reduce shame, confusion, and self-blame, and open the door to real, effective healing.
