Interoception: The Missing Link in Nervous System Regulation

Tight shoulders. A clenched jaw. Churning thoughts.

A vague fuzziness, chest hunched forward, the feeling of moving through fog…

We started this series by talking about how we can get stuck in an activated or shut-down nervous system state. And the goal, as we’ve established, is not to stay permanently calm or perfectly regulated. Real life doesn’t work like that.

The goal is flexibility.

We want a nervous system that can respond to stress, pressure, excitement, grief, challenge, movement, and connection – and then return toward a safe and settled baseline afterward.

But to regulate intentionally, we first need to recognise the state we’re in.

That’s where interoception comes in.

And honestly, this is the point where nervous system regulation starts shifting away from “a list of tools” and toward genuine self-awareness and agency. Because the practical value of interoception in nervous system regulation is this: recognising your state early enough to choose the right tool.

That’s the heart of this post.

You can think of the process like this:

bodily signals → nervous system state → awareness → tool selection → regulation flexibility

What Is Interoception?

Interoception is your brain’s ongoing sense of the physiological state of your body – the conscious and unconscious information your body sends upward about how it is doing internally.

This includes things like heart rate, breathing patterns, muscle tension, temperature, hunger and thirst, gut sensations, and the physical felt sense of emotions shifting in your body.

It’s part of what it feels like to be alive in your body. And importantly – interoception is not just emotional.

Your brain is constantly receiving updates from your body state. And those updates directly influence your nervous system regulation.

When this messaging system is out of balance, you might notice:

• Realising you were hungry only once you became ravenous
• Pushing through exhaustion until you crash
• Carrying tension in your jaw or shoulders without noticing
• Feeling “fine” all day, then suddenly overwhelmed
• Struggling to identify what emotion you’re actually feeling
• Not being able to connect into or feel individual muscles during movement

Some people experience interoception as very faint or muted – the signals are there, but the volume is turned down. Others experience the opposite: hyper-awareness of internal sensations, emotions, or body changes, where the volume feels overwhelming.

Both patterns can occur in dysregulated nervous systems. And both can improve with awareness and practice.

The Vagus Nerve: A Major Information Highway

To understand why interoception matters for regulation, it helps to briefly revisit the vagus nerve – we covered it in depth in The Vagus Nerve post.

The vagus nerve acts as a major communication highway between brain and body, travelling from the brainstem to organs and systems throughout the chest and abdomen. It carries information both downward from the brain and upward from the body.

Here’s the part that matters most: around 80% of vagal fibres are afferent – meaning they carry information from the body upward into the central nervous system.

Your brain is not only sending commands to the body. It is constantly listening to it.

Breathing, heart rate, muscle tension, digestion, facial expression, and vocal tone are all feeding information upward into the nervous system. That information is then integrated through networks involving the brainstem, insula, limbic system, and higher cortical areas to help your brain answer the questions it’s always asking: Am I safe? Do I need protection? Can I connect? Do I need to mobilise or withdraw?

Interoception gathers that information. And training your awareness of it lets you choose the right tools for regulation – both for immediate support and for long-term nervous system flexibility.

Note: Interoception is a big area. And understanding and teaching it is genuinely something I’m still learning too. If this interests you, I’ve linked a great resource at the end of this post that takes a much deeper dive into the physiology and practical application.

The Nervous System Compares Internal and External Cues

Your nervous system doesn’t interpret body signals in isolation. It constantly compares information from inside your body with information from your outside environment – a subconscious process Stephen Porges called neuroception.

External information arrives through your exteroceptive senses – sight, hearing, touch, taste, and smell. Internal information arrives through interoception. And layered in between are proprioception (body position and movement), vestibular input (balance and orientation), and social safety signals like voice tone, facial expression, and rhythm.

This is why movement, music, breathing, posture, grounding, and sensory input can all influence nervous system state. They change the information your brain is receiving…and your nervous system responds accordingly.

How Autonomic State Shapes Experience

One useful framework here is the polyvagal model, which describes three broad autonomic states:

• Ventral vagal: safe, connected, socially engaged
• Sympathetic: mobilised, activated, fight-or-flight
• Dorsal vagal: shut down, collapsed, disconnected

Your nervous system is constantly shifting between these depending on the information it receives – from both body and environment.

Here’s how that looks in practice.

Imagine you have an interview, presentation, or difficult conversation coming up. You might notice racing thoughts, tighter shoulders, quicker breaths, a faster heart rate, tension in your jaw or chest. Your body state changes first. And then those physical changes continue feeding information back upward – reinforcing the state.

But the same mechanism works in the other direction.

If you intentionally soften your shoulders, lengthen your exhale, slow your breathing, orient visually to the room, move your body, or ground through sensory input – you change the signals travelling upward. And that can help shift your overall autonomic state toward greater safety and regulation.

This is why the tools in this series work. You’re not tricking your nervous system. You’re changing the information it receives.

Better Awareness = Earlier Intervention

This is where interoception becomes genuinely practical.

By training interoception, we begin to notice cues from the body earlier. Not once you hit “I’m overwhelmed”, but:

• “My shoulders are creeping upward.”
• “My breath is becoming shallow.”
• “I’m clenching my jaw.”
• “I’m speeding up.”
• “I’m starting to feel scattered.”
• “I’m withdrawing.”
• “I’ve stopped noticing hunger or fatigue.”

Earlier awareness gives us more options. And usually, the earlier we intervene, the less extreme the nervous system response becomes – and the easier it is to choose tools to brings us back to our window of tolerance, or toward that safe-and-connected ventral vagal state.

We cannot regulate signals we do not notice.

Awareness Builds Flexibility and Resilience

Over time, practising interoception helps us build a more detailed map of our own nervous system patterns. We begin to recognise what activation feels like in our body. What shutdown feels like. What safety feels like. What helps us shift state – and what pushes us further into dysregulation.

That’s where nervous system regulation becomes genuinely individual and genuinely empowering. Not because we eliminate stress. But because we become more flexible, more responsive, and more aware.

So we’re going to finish today with a simple body scan exercise – a practical introduction to bringing attention to the structures and sensations involved in interoceptive awareness.

This is a gentle introduction to interoceptive awareness.

Try it regularly. It can help to keep brief notes: over time, many people find their awareness becomes clearer, earlier, and more nuanced.

And remember what we’re building with this practice:

bodily signals → nervous system state → awareness → tool selection → regulation flexibility

As you build your interoceptive connection and skill, regulation becomes less reactive and more intentional. That shift, from reacting to intentional, regulated response, is what this whole series has been building toward.

I’m loving learning more about regulation, and exploring it in my own practice. I truly hope that the learning is bringing more ease and connection to your life too.

🤍 Carmen

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Resources and further reading

Reference for this post:

📖The Nervous System Reset by Jessica Maguire

Other posts in this series:

📃 Start here: Your Body Is Not the Enemy: Understanding Nervous System Regulation

🎨 Using Creativity for Nervous System Regulation: A Gentle Way Back Into Your Body

😤 Breathing for Nervous System Regulation: Simple Ways to Feel More Settled in Your Body

🚶‍➡️ Why Movement Regulates Your Nervous System (And How to Use It)

🩻 The Vagus Nerve Explained: A Practical Guide to Nervous System Regulation

🌻Before You Go Inward: How Your Body Builds a Sense of Safety