PTSD isn't about the past. It's about a nervous system that got stuck there. Once you understand what's actually happening in your loved one's brain, a lot of what looked like rejection starts to look like a body trying to keep them safe.
The past, still happening
Psychiatrist Bessel van der Kolk spent decades studying what trauma does to the brain and body. His central finding, documented in The Body Keeps the Score, is that traumatic experience is not stored like an ordinary memory. It is stored as a physical state the body returns to. A sound, a smell, a tone of voice. The nervous system reads it as danger and the threat response fires before there is any time to think.
Your loved one isn't choosing to react that way. The part of the brain that would normally signal safety went offline during the original trauma, and the survival system is running the show. That's why a calm conversation can flip in seconds. That's why the smallest thing can become the biggest thing.
Hypervigilance is exhausting from the inside too
Psychiatrist Stephen Porges developed the Polyvagal Theory to explain how the autonomic nervous system constantly scans the environment for cues of safety or danger, a process he calls neuroception. In people with PTSD, that scanner is set to high alert. They notice the exit in every room. They flinch at sounds you don't hear. They can't settle, even when nothing is happening, because their nervous system is certain something is about to.
It costs them enormously. It costs you too. Living alongside a nervous system in overdrive will pull at your own. Researchers call this co-regulation: we are wired to pick up on each other's physiological states. That isn't your weakness. That's two people in a room, one of them in a state the other one can feel.
“Your loved one isn't pushing you away. Their nervous system is doing what it learned to do.”
Triggers aren't logical, and that's not a flaw
Judith Herman, whose foundational work Trauma and Recovery shaped how clinicians understand PTSD, wrote that traumatic symptoms simultaneously demand and defy speech. The link between what's happening now and what happened then can be invisible, even to your loved one. They may react without knowing why. You may react to their reaction and also not know why.
The work is not to map every trigger. The work is to stop expecting the response to look reasonable from the outside when the inside is running a completely different programme.
What actually helps
Predictability helps. A calm, consistent tone of voice helps. Slower pace, quieter environment, fewer questions in the moment. Van der Kolk's research consistently shows that the path back from a triggered state runs through the body, not through logic. Naming what is present, gently: 'I'm here. We're in the kitchen. It's Tuesday.' Grounding in the senses. Quiet.
What doesn't help: reasoning with a survival brain when it is online, taking the response personally, or trying to fix it in the moment. The window for conversation opens after regulation, not before.