How Trauma Shapes the Nervous System
Trauma can leave a lasting imprint on both the mind and body. When danger or threat is experienced repeatedly or intensely, the nervous system adapts to protect you. Over time, these protective strategies can persist, influencing how you feel and respond long after the danger has passed.
The nervous system can adapt in different ways to cope with threat. Two common patterns include high alert and shutdown. These are not opposites; rather, they are survival responses that can shift depending on the situation or even alternate quickly in the same person.
High Alert: When Trauma Keeps You Ready
One way the nervous system adapts to trauma is by remaining in a constant state of alertness. It keeps scanning for danger, anticipating that a threat could arise at any moment. If you grew up or lived in an unpredictable, unsafe, or stressful environment, your body may have learned that staying prepared for danger was the safest option. Over time, this state of readiness can become the default, even when the environment itself is no longer threatening.
Signs of high alert may include:
Feeling tense, restless, or “on edge”
Being easily startled by sounds or sudden changes
Difficulty concentrating or relaxing
Heightened emotional responses, such as irritability or anxiety
Even in safe environments, the body may react as if a threat is still present. Trauma leaves behind a nervous system tuned to survival, making ordinary events feel risky or overwhelming.
Supporting the nervous system in high alert:
Practise slow, regulated breathing
Use grounding and body awareness techniques
Engage in gentle, controlled movement
Seek trauma-informed therapeutic support
Shutdown: When Trauma Causes the Body to Pull Away
At other times, the nervous system responds by withdrawing. Instead of staying alert, it lowers arousal and disconnects from sensation and experience, as a form of protection. This can occur in many situations: during a heated conflict where escape feels impossible, the body may switch off; a child who grows up with neglect may learn to numb their feelings as a way of coping; lying in a hospital bed, unable to move or influence what happens, can prompt a shut-down response. In cases of abuse, when fighting back or leaving is not an option, the body may reduce awareness of sensations to blunt the impact.
Signs of shutdown may include:
Feeling detached or zoning out
Reduced awareness of bodily cues, like hunger or fatigue
Difficulty connecting with others
Low energy or emotional numbness
This, too, is a survival strategy. When fight or flight is unsafe or impossible, the body conserves energy and lessens the impact of stress. While this once helped you endure, it can also leave your body and mind disconnected from the present.
Supporting the nervous system in shutdown:
Use grounding through the senses
Introduce small, safe body movements
Reconnect with trusted people
Seek trauma-informed therapeutic support
Trauma Responses Are Adaptive, Not Flaws
Both high alert and shutdown reflect the nervous system’s intelligence in keeping you safe. Trauma teaches the body and brain strategies that worked in dangerous circumstances, even if they no longer serve you in daily life.
Recognising these patterns is the first step toward healing. With gentle, structured support, it’s possible to retrain the nervous system to respond to the present rather than old threats - restoring presence, connection, and a sense of safety.