Understanding your nervous system — and how to work with it
You’ve probably had a day where your heart was racing, your mind wouldn’t stop, and no matter how many times you told yourself to calm down — you just couldn’t.
Or maybe the opposite — a day where you felt completely flat. Empty. Like someone had switched the lights off inside you, and you couldn’t find the switch.
Neither of those experiences means something is wrong with you. They mean your nervous system is doing exactly what it was designed to do.
And once you understand that — everything changes.
Meet Your Nervous System
Your nervous system is your body’s brilliant, ancient alarm and safety system. It works 24 hours a day, scanning your environment for signals of danger or safety — mostly without you even knowing.
It doesn’t just respond to what’s actually happening. It responds to what it perceives might happen, based on everything you’ve ever experienced. It’s incredibly fast, incredibly sensitive, and incredibly wise.
The science of how this works — Polyvagal Theory, developed by neuroscientist Dr Stephen Porges — gives us a language to understand what’s happening inside us. And understanding it is genuinely life-changing.
There are three key states your nervous system moves through. Think of them as floors in a building.
The Three Floors
🟢 The Middle Floor — Your Window of Tolerance
This is home. This is where you feel calm, connected, and present. Where you can think clearly, make good decisions, feel warmth toward others, and engage with life.
Technically, this is called ventral vagal activation — your social nervous system is online, your brain is fully available, and your body feels safe enough to simply be.
This is where healing happens. Where learning happens. Where genuine connection happens.
You feel: curious, grounded, warm, clear-headed, capable, open.
🔴 The Top Floor — Hyper-Arousal
When your nervous system detects threat — real or perceived — it sends you upstairs fast. This is your sympathetic nervous system mobilising for survival.
Adrenaline surges. Heart rate climbs. Muscles tense. Your thinking brain steps back, and your survival brain steps forward.
This is brilliantly useful if you need to swerve to avoid a car. It’s exhausting if it’s triggered by an email, a crowded room, or a memory.
You feel: anxious, irritable, overwhelmed, restless, panicky, unable to switch off, on high alert.
This is the fight or flight response — and sometimes a kind of active freeze, where your body is flooded with energy but you feel paralysed.
🔵 The Bottom Floor — Hypo-Arousal
Sometimes the threat feels too big, too long, or too inescapable. When that happens, your nervous system can do something else entirely — it shuts down.
This is the dorsal vagal response. Your body withdraws. Conserves. Goes quiet. It’s an ancient survival strategy — used by animals when fight or flight won’t work — and it’s just as valid, just as automatic, and just as involuntary.
You feel: numb, disconnected, foggy, exhausted, empty, flat, like you’re going through the motions, not quite there.
This isn’t weakness. This isn’t laziness. This is your body protecting you the only way it knows how.
So — Am I In My Window of Tolerance Right Now?
Ask yourself:
Can I think clearly and make sense of what’s happening? Do I feel present and connected — to myself, to others? Does my body feel relatively calm?
If yes — you’re in your window. Wonderful. Stay there as long as you can.
If not — you’ve likely moved into hyper or hypo arousal. And that’s okay. Here’s what helps.
When You’re Hyper-Aroused (Too Activated)
Your system needs help coming down. The goal is to signal safety to your nervous system — gently, physically.
Try these:
🌬 Physiological sigh — a double inhale through the nose, then a long slow exhale through the mouth. This is the fastest scientifically-backed way to downregulate your nervous system.
🎵 Hum or sing — this one surprises people, but the science is beautiful. Your vagus nerve — the master regulator of your nervous system — runs directly through your throat and vocal cords. When you hum or sing, those muscles vibrate and literally stimulate the vagus nerve from the inside. Research shows it synchronises heart rate, releases oxytocin, and the long slow exhale that singing requires activates your parasympathetic brake. You don’t need to be able to sing. Hum in the car. In the shower. Nobody even needs to know you’re doing nervous system work.
🖐 5-4-3-2-1 grounding — name 5 things you can see, 4 you can touch, 3 you can hear, 2 you can smell, 1 you can taste. This anchors your brain in the present moment.
🧊 Cold water — splash cold water on your face or hold your wrists under cold running water. This activates the dive reflex and slows your heart rate.
🚶 Slow, rhythmic movement — a gentle walk, swaying, even rocking. Rhythm regulates. Your nervous system loves rhythm.
When You’re Hypo-Aroused (Too Shut Down)
Your system needs gentle activation — not force, not pressure. The goal is to slowly wake things back up.
Try these:
☀️ Sunlight and fresh air — step outside, even briefly. Natural light and gentle sensory input can begin to lift the fog.
🎵 Music with a beat — uplifting, rhythmic music can gently bring the body back online. Movement to music is even better.
🫂 Safe connection — a conversation with someone who feels safe to you. The social nervous system is a regulator. We co-regulate with each other.
💧 Warm drink, slow sips — the act of tasting, swallowing, and warming from the inside can gently cue the body back to presence.
🖊 Journalling — even two minutes of writing can help you reconnect with your inner world when you feel lost in the numbness.
One Last Thing
Your window of tolerance isn’t fixed. It can grow.
Through therapy, through practice, through safe relationships, and through learning to understand your own nervous system — your capacity to stay regulated gets bigger. The storms don’t disappear, but you become better at riding them.
Your nervous system isn’t your enemy. It’s been working overtime to keep you safe, often for a very long time.
Learning its language is one of the most profound acts of self-compassion there is.
If you’d like support in understanding your nervous system and building your window of tolerance, I’d love to work with you. You can find out more about working with me here.
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