Surviving Insomnia Chapter 13: Surviving Insomnia Begins in the Body: Getting to Know Your Nervous System

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Introduction

The entire human experience from misery to Joy, from boundless excitement to boredom to blissful sleep and everything in between happens within in our physical bodies (embodied) and the physical and social world that surrounds us (embedded). All our experiences, pleasant or unpleasant, wanted or unwanted occur within and are driven by this embodied and embedded situation. 

For now, I’m going to focus only on the embodied part. Just remember that this embodiment is always happening in the embedded context of the external environment and relationships. 

It’s useful to look at this embodied situation through the lens of Polyvagal Theory (PVT), which says that our autonomic nervous system (ANS) is the physical platform on which ALL behavior and experience occur. It says that your nervous system shifts into different modes of safety or defense based on the signals or cues of safety and danger it receives from inside and outside the body. This theory provides us with a physical “map” of how safety and defense are biologically organized. From the PVT perspective this map has three main modes. One of safety and two of defense, each named after a part of the ANS:

1. The mode of ventral vagal safety, connection, and calm where the body can access health, growth, and restoration. 
2. The mode of dorsal vagal defense characterized by immobilization, under-activation, and hypo/under-arousal where the body is shut down and conserving energy.
3. The mode of sympathetic defense characterized by mobilization, over-activation, or hyperarousal where the body is ready to fight or escape. 

You may have heard of fight, flight, and freeze responses. Those words refer to how our body feels and acts when in defense modes. You may have heard these modes referred to negatively, as if something is wrong if you are in a defense mode. I’d like to correct that view. Defense modes are not signs of failure or brokenness. They are adaptive, useful responses, and your nervous system’s way of trying to keep you safe in a world that has, at times, felt unsafe. Whether you’re mobilized into anxiety or frozen in shutdown, these are not flaws, they’re the body’s best effort to take care of you. 

 The more you can view the defense modes through this compassionate lens and think about your nervous system as, “just doing its job,” the more useful what you learn here will be.

How interesting…but how will this help me feel and perform better during the day?

It is important for you to understand this map and be able to recognize these modes for two reasons: 

One, because the range of behavior and experiences you capable of having is limited by the mode of your nervous system. This means that no matter what the situation, you may find yourself unable to feel or do what is desired, necessary, or appropriate. Instead feeling and doing things that are inconsistent with your own best interest, make the situation worse, or are plain don’t fit with what is right for the situation. This means: 

• If you are stuck in a dorsal defense mode, you will not be able to reach for connection, and you’ll likely be withdrawing, feeling numb, or shutting down—even if you long to be close to someone.
• If you’re stuck in a sympathetic defense mode, you will not be able to relax and think clearly, and you may find yourself reacting impulsively, speaking sharply, or obsessing about something minor—despite wanting to stay calm or move on. 
• And even when you touch a ventral mode of safety, if a defensive mode is still blended in, you may find it hard to trust the good moment or accept rest—feeling instead like you’re waiting for the other shoe to drop.

Two, spending more time in a mode of safety will also make whatever sleep you do get more restorative. One of the major jobs that sleep does for you is “taking out the garbage.” A system in the brain called the Glymphatic System pushes cerebrospinal fluid throughout the brain to clear out the waste produced by your brain. Your ANS is the engine of this system. When you are in a mode of safety, your nervous system drives your glymphatic system to perform at its best. When your nervous system is in a defense mode, the engine is weak and you’re the system works poorly.

Although the glymphatic system is working during sleep and wakefulness, most of the work is done at night, especially when you are in deep sleep. Think of it like a cleaning crew for a business. During the day there might be a couple of cleaning staff or maybe a daytime employee who’s responsible for tidying up and cleaning up occasional messes. Yes, they are going to keep the place from getting particularly nasty but not really going to keep it clean. Then all the customers and employees go home, and the full cleaning crew shows up. This crew’s sole job is to clear out the garbage, get everything reorganized, and clean up the dirt and grime that accumulated throughout the day. Not only do they have the workforce, but they also have special tools to do the job. When daytime comes the place is clean and organized and ready for business. 

This may sound discouraging. But it also means that if you change your autonomic mode (AND YOU CAN!), you shift the probability (and possibility) that your desired feelings, behaviors, and experiences will arise. And the more you guide your nervous system into a mode of safety, the more restorative whatever sleep you do get will be and the better you’ll feel and function during the day. 

 This is good news because you CAN change your mode. In this book, I am going to teach you how.

 But first, you must learn to know what mode you’re in.

I’m in! So how do I know what mode my nervous system is in?

Let’s look at how each mode is experienced and how they look and feel in general, and then I’ll teach you a technique for beginning to recognize your own modes.

Hopefully, you now know and believe that your ANS has three main modes of safety (ventral vagal), defensive immobilization or under-arousal (dorsal vagal), and defensive activation or hyperarousal (sympathetic). As an insomnia sufferer, your ANS can be in any one of these or some mixed combination of them.

 Here are descriptions of what these might look like for you as a person with insomnia:

Ventral Vagal (Safety)

This is your nervous system’s “happy place.” When in this mode, you can comfortably and flexibly deal with whatever the day brings, and your body can perform all the functions necessary for health, growth, and restoration (including sleep). Importantly, ventral vagal safety isn’t just feeling calm or still—it can also feel energized, alive, and motivated. This mode supports not only rest but healthy engagement with the world. When the nervous system feels safe, it frees up energy for creativity, flow, productivity, playfulness, curiosity, and spontaneous joy.

When you are healthy, you can easily get into this mode and spend much of your time here. But when you struggle with insomnia this mode can be difficult to access, with only brief moments of ventral vagal safety available during the day or night. One of our goals in this program is to help you savor and take advantage of this mode when it is show up and learn skills for guiding your nervous in this direction. Here is what this mode might be like:

• Feels like: Calm presence, grounded vitality, a sense of “okayness” or even quiet excitement. You may feel emotionally available, grateful, connected—or even energized and inspired.
• Behaviors: You may pause to enjoy a moment, reach out to someone, move with purpose, speak with warmth, or allow yourself to rest without guilt. You might laugh, sing, or feel drawn to creativity or connection.
• What others might notice: Softer facial expression, brighter eyes, engaged body language, warmer tone of voice, and a sense of being more approachable, playful, or emotionally present—even if just briefly.

Dorsal Vagal (Defensive Immobilization or Under-Arousal)

While your nervous system can be dramatic in this mode (literally passing out), this mode often typically shows up as a quiet, persistent depletion of energy, motivation, and connection. It may be mistaken for laziness, depression, or lack of willpower—but it is actually a survival response: the nervous system’s way of conserving energy when it perceives continued threat and exhaustion with no workable escape or resolution.

• Feels like: Numbness, emptiness, disconnection, profound fatigue. You may feel invisible or like giving up.
• Behaviors: Withdrawing from social contact, avoiding tasks, staying in bed, or moving slowly and minimally.
• What others might notice: Emotionally distant, low energy, minimal speech or eye contact, “checked-out” demeanor.

Sympathetic (Defensive Activation or Hyperarousal)

This mode can dominate both night and day for those with insomnia. It’s the mode of a nervous system that is constantly scanning for danger, even when there’s nothing “objectively” threatening in the moment. In this mode, the body is primed for action, not rest—which can look like being wound-up, agitated, or tightly focused on control. Unlike dorsal shutdown (which looks like collapse), sympathetic activation looks like an overdrive mode—driven by tension, urgency, and the need to keep going despite depletion.

• Feels like: Wired and tired, anxious, panicky, driven by urgency or frustration. You may feel like your body is moving faster than your thoughts can keep up.
• Behaviors: Over-planning, over-researching, difficulty sitting still, compulsive “doing” to avoid stillness.
• What others might notice: Quick speech, muscle tension, irritability, fast movements, emotional reactivity.

Polyvagal Theory also recognizes that autonomic modes aren’t black and white. Instead of flipping cleanly from “safety” to “defense,” the nervous system sometimes exists in blended or transitional modes—especially when healing from chronic dysregulation. So, you might find yourself in one of these mixed modes:

Mixed Defense (Dorsal Vagal + Sympathetic)

This mixed mode—where the sympathetic (mobilized) and dorsal vagal (immobilization) systems are both active—can result in one of the most distressing and confusing experiences. It’s like trying to drive with one foot on the gas and the other on the brake. This mode often creates a sense of being frozen but frantic, tired but agitated, or numb on the outside, panicking on the inside—and is especially common in individuals with insomnia.

• Feels like: Torn in two directions. You may feel exhausted but restless, numb but anxious, overwhelmed but unable to act.
• Behaviors: Pacing, doom-scrolling, zoning out while feeling intense inner urgency or dread.
• What others might notice: Glazed eyes with agitated behavior, frustration that seems to “come from nowhere,” frozen posture with signs of inner tension.

Mixed Safety and Defense (Ventral + Sympathetic or Dorsal)

Mixed modes that include ventral vagal safety are possible, and in fact, they’re often what healing looks like for someone with insomnia. A ventral vagal mixed mode means that cues of safety and connection are present, but co-existing with mobilization (sympathetic) or immobilization (dorsal) responses. 

These mixed modes may feel bittersweet, tentative, or ambivalent—but they’re also a hopeful sign that the nervous system is regaining flexibility. In my individual work, I see return of the ability to nap or unintentional dozing during meditation or prayer as positive signs that the nervous system is learning to move toward safety. 

• Feels like: Hopeful but cautious, capable but uncertain, curious but guarded. You may notice a flicker of motivation or connection even amidst fatigue or anxiety. There may be brief moments of aliveness, creativity, or inspiration—though they might feel fragile or fleeting.
• Behaviors: Taking small steps toward connection, rest, or self-care—sometimes pulling back, then trying again. You may start a meaningful conversation, get a burst of energy to tidy a space, or feel drawn to music or nature.
• What others might notice: Brief moments of lightness or engagement, a softened tone, increased eye contact, or spontaneous laughter. There may be subtle signs of emotional vitality—like expressing gratitude, humor, or curiosity—even during struggle.

How will this help me sleep?

When your nervous system is in a defense mode, the body’s restorative physical behavior shuts down. Sleep is a behavior, a physical restorative process that requires your nervous system to be in a mode of safety. Sleep is also something your body does, not something you do. This means your ability to sleep is at the mercy of your physical mode and there is nothing you can do to force yourself to sleep when your nervous system is in a mode of defense. If you are in one of the defense modes, sleep will be difficult and poor at best and completely unattainable at worst. The more skilled you become at bringing yourself into a mode of safety during the day, the more likely you will be in a mode of safety that supports sleep when bedtime comes.

EXERCISE: Personal Nervous System Stories

Inspired by Deb Dana’s Autonomic Landmarks exercise, this reflection helps you capture a “snapshot” of each nervous system mode based on your unique experiences. The goal here is to start to get a sense of what each mode looks and feels like for you.

Complete these steps for each of the modes I just described. 

1. Read the description of the mode.
2. Think of a moment from your daytime life when you remember feeling and acting that way. If you come up with multiple memories, choose the one with the strongest thoughts, emotions, and body sensations. 
3. In a few sentences or bullets, write a story describing the details of the experience.

• What was happening?
• What were you doing and who were you with?
• What were you feeling in your body?
• What were your thoughts and emotions?

Key idea: You don’t need to control your mode—for now, you only need to notice it. Awareness is the first step toward change.

Summary

This chapter introduced you to the foundation of how your nervous system shapes every moment of your waking and sleeping life. Using the lens of Polyvagal Theory, you learned that your autonomic nervous system (ANS) works as the physical platform for all behavior, emotion, and experience. It continuously shifts among three main modes—ventral vagal safety, sympathetic mobilization (fight/flight), and dorsal vagal shutdown (freeze/collapse)—based on cues of safety and danger from both inside and outside your body. 

You discovered that defensive modes aren’t signs of weakness or damage, but natural, adaptive attempts by your body to protect you. However, when you get stuck in these defensive modes, your range of emotions and actions becomes limited, and restorative processes—like experiences of flow, close connection, and refreshing sleep—become harder to access. You started to become familiar with how each of the five ANS modes looks and feels for you by completing the Personal Nervous System Stories exercise. 

In part 2, you’ll learn about perception and neuroception, continue growing awareness of your nervous system, and begin developing the skill of turning to a mode of safety.