11/15/2025
When we talk about PTSD, we often think about memories, triggers, or emotional reactions…
but underneath all of that is something deeply physiological happening inside the body.
One of the most profound shifts researchers see in people with chronic trauma is this:
The body develops more cortisol receptors.
Why does this matter?
Because cortisol is the hormone your body releases when it senses danger.
It’s meant to spike, help you respond, and then fall once the threat is gone.
But with prolonged stress or trauma, the system becomes overloaded.
Your cells begin to up-regulate - meaning they create more cortisol receptors so they can “catch” more of the stress hormone circulating in your bloodstream.
It’s the body’s way of saying:
“I need to be ready for anything. All the time.”
This is where the HPA axis (the hypothalamus–pituitary–adrenal loop) becomes disrupted.
Normally, it works like a thermostat:
• Stress rises
• Cortisol is released
• Cortisol sends a message back up the chain saying, “We’re safe now, you can turn off.”
But with PTSD, this negative feedback loop is weakened.
More receptors = stronger sensitivity to stress.
Stronger sensitivity = the “off switch” doesn’t work as easily.
And the system that is meant to calm you…can’t.
This is why people with trauma may feel:
• Wired but exhausted
• Startled easily
• Flooded by minor stressors
• Hyperaware of surroundings
• Difficulty winding down or sleeping
• “On guard” even during calm moments
Not because they’re dramatic.
Not because they’re overreacting.
Not because they’re not trying.
But because their biology adapted to threat.
And here’s the hopeful part:
These patterns can shift.
Through nervous system work, somatic therapy, EMDR, softening practices, breath, safety, connection, and time -
the body begins to recalibrate.
Cortisol receptors down-regulate.
The HPA axis becomes more responsive again.
Your system remembers what it feels like to stand down.
Healing isn’t about forcing calm.
It’s about teaching the body that it no longer has to live in survival mode.
Your biology is not broken
it has been protecting you.
And it can learn something new.