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The Neurobiology of Freaking Out: The Window of Tolerance

Updated: Mar 21, 2023

Lest any of you think therapists are better at life than you are, here is a true story that just happened last week:

I’m driving my daughter to daycare; it’s a twenty-minute trip mostly along C-470. I have recently purchased new car insurance, so I’m using one of those apps that tracks your driving to see if you qualify for a lower rate. I got an alert the night before that my score is not all that great and I’m headed for a rate increase. I’m pissed off about this. It’s not fair! I’m a good driver! I say to myself as I continue driving 80mph along the highway (it has a 65mph speed limit, but whatever).

We are listening to Encanto. We have been listening to Encanto every morning (and afternoon, and evening) for several weeks now; it’s my 2-year-old’s current favorite. Then she suddenly calls out.

“No ‘Tanto! No ‘Tanto!”

“What? No more Encanto? What else do you want to listen to?”

“No ‘Tanto!”

“I hear you, baby. What else do you want to listen to?”

“Manana!” (Moana, her other favorite Disney soundtrack)

“Okay, I’ll turn on Moana,” I tell her, disgruntled about having to use my phone and rack up another point against me with my car insurance company. “You’ll just have to wait a minute.”

She begins shrieking. Continued cries of “Nooooo! No ‘Tanto! No ‘Tanto!” are intermingled with screeches of outrage.

My body responds immediately. My muscles tense up, causing my hands to grip the steering wheel a little tighter. My heart starts pounding; I can feel it pulsing in my temples, creating too much pressure in my head. My chest feels suddenly hot.

“STOP SHOUTING AT ME!” I shout at her. As I try to twist around and fix her with a death stare, the car swerving slightly.

And there goes my premium—up, up, up and away.

What just happened?

Well, a lot of things. But we’ll get to that.

All of us have been there—losing our tempers, getting caught in a cascade of anxiety, acute and overwhelming stress causing us to act like absolute maniacs. All of us have probably been on the opposite side of the spectrum, too—sitting on the couch, staring at the wall or zoned out on our phones, feeling paralyzed and completely unable to get started on the mountain of tasks awaiting us or deal with an unbearable relationship conflict. When I get stuck in either of these two extremes, it sometimes feels like I’m not even myself anymore. Gone is the calm and capable professional, the affectionate and fun-loving mother, or the creative and energetic entrepreneur; all that’s left is a crazy woman who can no longer function like a grownup. It’s a little embarrassing.

It doesn’t have to be embarrassing, though. It’s a universal experience. It happens to all of us. And it’s not a moral failing. It’s just our brain’s way of coping with stress; our brain is just trying to protect us from an amount or type of stress that feels dangerous and overwhelming.

Let me explain the neurobiology of freaking out.

I walk through this concept with most of my clients at one point or another, and quite often, I watch the expressions on their faces change as the burden of guilt and self-judgment over whatever freak-out we were just discussing starts to fall away.

I like to explain the neurobiology of freaking out (or shutting down) using a model called the Window of Tolerance. This concept was developed by Dr. Dan Siegel, a psychiatrist with a background of extensive neuroscience research, and you can read more about it in several of his books, including Mindsight. Other authors conceptualize the same neurobiological concepts in other ways (for example, Mona Delahooke, author of Body-Brain Parenting, uses “green, blue, or red pathways”). The simple terms that I sometimes use are “meltdown” vs “shutdown.” But the science behind all of these terms is the same.

So let’s break down the Window of Tolerance.

There are three areas where we can fall on the Window of Tolerance at any given time: Inside the Window, in our optimal zone of functioning, or outside the Window into either Hyperarousal or Hypoarousal. All three of these areas represent different ways our nervous systems are impacting our bodies. Without getting too technical, I’ll just say that the three areas (Hyperarousal, Inside the Window, Hypoarousal) indicate different branches of our autonomic nervous system (ANS) that are dominant in our functioning.

The ANS controls the functions of our body that are automatic, such as respiration, blood pressure, heart rate, digestion, etc. When we’re at rest, inside our Window of Tolerance, our brain functions optimally; our body is in balance and we are calm, able to socially engage, able to use the full capacity of our executive functioning (self-control, problem-solving, logical reasoning, etc.), and able to make choices in line with our values. Inside the Window, we are grounded in our bodies, fully present, open to new experiences and able to respond with flexibility and self-regulation. This is where we want to be the majority of the time; we’re at our best, and it feels good.

When a big stressor comes in, one of two responses gets activated: Hyperarousal or Hypoarousal. When we’re in Hyperarousal, it’s like pressure is being applied to the accelerator in our nervous system: our prefrontal cortex (the seat of executive function) goes “off line” and faster, more reactive areas of our brain take over; our muscles tense, our heartrate increases, our breathing speeds up, and our body prepares to take action in a fight-or-flight response. This often feels like either anger or anxiety.

In contrast, when we’re in Hypoarousal, it’s like someone has slammed on the brakes and everything is grinding to a halt: our body slows way down, leaving us feeling numb, paralyzed or frozen, depressed, stuck in shame, or even dissociating (a sort of mental vacation from the body); energy is zapped, our thoughts feel like thick mud, and I know for me personally, my body sometimes feels cold or heavy. In Hypoarousal, our brain has decided fight-or-flight won’t work, and turns instead to the “freeze-or-faint” response for maximum self-preservation (like the animal that plays dead when it can’t escape the predator).

What sends us over the edge of our Window of Tolerance?

Let’s start by redefining the word “stress.” Most of us, when we think of stress, think of having too many tasks to accomplish or too many things to worry about. But psychologically (and physically), stress is a much broader category. Stress can be anything that our brain senses as a threat. Here are some examples:

The baby cries. Your brain says: “It’s an attachment threat!” The car behind you honks angrily. Your brain says: “It’s a safety threat!” You open your email at work and find six messages from your boss. Your brain says: “It’s an energy threat!” or “It’s a reputation threat!” or (if you’re the primary breadwinner and you immediately jump to a fear of getting fired) “It’s a survival threat!” Your partner says, “Hey, we need to talk.” Your brain says: “It’s a relationship threat!” You step on a Lego in the middle of the night. Your brain says: “It’s a physical threat!” You smell dinner burning in the other room. Your brain says: “It’s a survival threat!” (whether your brain is more worried about surviving a structure fire or starvation probably depends on other factors)

Starting to get the picture? Our brains are constantly on the lookout for threats. After all, they need to keep us alive. What better way to keep something alive than to be alert to any and all possible threats, in order to mount an instantaneous defense?

And when those threats come in, our position on the Window of Tolerance—and the way our brains and bodies are functioning—shifts in response. We may go up toward Hyperarousal, activating our fight-or-flight response and flooding our body with energy to deal with the threat. Or, if our brain decides that fight-or-flight won’t work and we’re helpless to manage the threat, we may go down toward Hypoarousal, freezing or shutting down to minimize the impact and distress of the threat.

One last thing I want you to remember about the Window of Tolerance: If you feel like you are spending way more time in Hyperarousal or Hypoarousal than you would like, this may be because your Window has become narrow, meaning that you are hypersensitive to threats and your body has difficulty regulating in response. What can make your Window of Tolerance narrower? Lots of things, from lack of sleep or an illness to chronic stress or a history of trauma. More on this in upcoming blog posts.

So let’s go back to my car as it’s speeding along C-470 on a Tuesday morning.

What happened? First, let’s back up. My daughter had woken three times during the night; I was tired, and my Window of Tolerance was narrower because of it. We were running behind schedule, and I was worried about looking unprofessional by showing up late to a session—a threat that had pushed me up to the top edge of my Window. Because I had been rushing, I hadn’t had an extra moment to connect relationally with my daughter; she was feeling neglected, which is really dysregulating for toddlers and had pushed her closer to Hyperarousal. Then the trigger happened: my daughter couldn’t get what she wanted, and this pushed her into Hyperarousal; her screams of protest pushed me the rest of the way out of my Window of Tolerance. Chaos ensued.

What I want you to take away from this, beyond just a deeper understanding of how your body responds to stress and makes decisions for you, is that it’s not the end of the world. We can learn how to regulate, how to get ourselves back in the Window of Tolerance. With practice over time, we can widen our Windows. We can teach our children how to get back inside the Window. And when all else fails, we can repair.

By the time we got to daycare, I had wrestled my body back under control. I parked, took a deep breath, let it out, and got out of the car. I opened the door and kissed my daughter on the forehead before I unbuckled her.

“Mommy is sorry for yelling, baby girl. I shouldn’t have done that. I just got scared because we were driving, and it wasn’t safe to change the music. We’ll do better next time.”

My repair—loving relational engagement, a calm voice, an acknowledgement of my rupture—allowed her body to regulate. She smiled, grabbed her toy cars, and walked hand-in-hand with me into daycare.

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