Hypoarousal and Hyperarousal: How to Tell Which State You're In
What is hypoarousal? And how is it different from hyperarousal? In my time as a clinician, I have found it helpful for my clients to learn about these nervous system states. By learning about the nervous system, we are better able to observe ourselves and give our bodies what they need from moment to moment.
In this article, we will learn about hypoarousal, hyperarousal, and the window of tolerance. With this understanding, we can begin tracking our nervous system to figure out where we are at any given time. Then, we can begin introducing practices that will expand our capacities and help us live more present, grounded, and engaged lives. If you’d like more information about the nervous system and ways to begin building capacity, check out my comprehensive article on the nervous system. As a clinician specializing in neurodivergence, I also have a workbook dedicated to the neurodivergent nervous system with lots of deep-dive information, guides, and fillable workbook pages.
The Window of Tolerance
Before we dive into hypoarousal and hyperarousal, let’s first talk about the window of tolerance. Our window of tolerance is a way of conceptualizing our bandwidth or capacity to tolerate intense emotions. Specifically, it refers to our bandwidth or capacity for tolerating intense emotions at the sympathetic end and bored, numb, or low feelings at the parasympathetic end.
The window of tolerance is the zone where intense emotions and stress can be adapted to and processed in healthy ways. When in this window of tolerance, you can react to stress, anxiety, and intense emotions effectively. When you have a large window of tolerance, it means you have a great deal of capacity to deal with stress which allows you to respond to the demands and stress of everyday life without too much strain.
When we are present, calm, grounded, and engaged, we are in our window of tolerance. The window of tolerance is a nervous system state where both our sympathetic nervous system (the part of our nervous system responsible for mobilizing us for action) and our parasympathetic nervous system (the part of our nervous system responsible for our rest and digest response) work together in harmony. When we are within our window of tolerance, these two branches of our nervous system work together seamlessly like the gas and brake pedal in a car. They operate in synchrony to create a smooth driving experience.
However, if we are faced with more stress than we can handle within this window, we exit the window of tolerance, becoming dysregulated and entering a stressed body state. When we are dysregulated, we can become either sympathetic dominant (hyperarousal) or parasympathetic dominant (hypoarousal). Let’s get into what that looks like.
Hypoarousal
Most people think of stress and associate it with the fight-or-flight response. However, our bodies can also respond to stress by becoming hypoaroused. If we are hypoaroused, our parasympathetic nervous system takes over to shut us down. This happens when we face too much stress or “charge” in the body, and our nervous system protects us from overwhelm by shutting us down.
Hypoarousal occurs on a spectrum. A person may have mild experiences of feeling foggy, disconnected, and fatigued or may have a complete freeze response (become immobilized and can’t move), as can happen in the context of extreme trauma. Personally, when I am sensory overloaded, my body responds by going into a hypoarousal state. My senses dull, I become heavy and tired, and there is a fogginess that takes over me. This would be an example of a more mild form of entering a hypoaroused state (side note: for ADHDers and Autistic people, sensory overload can absolutely trigger us out of our window of tolerance).
Let’s take a closer look at the signs of hypoarousal:
Traits of Hypoarousal
Mental and Emotional Traits:
brain fog
dissociation
lack of focus
sleepiness
fatigue
shut down
low energy
numbness
depression
technology addiction
cravings for substances
Physiological Traits
irregular heartbeat
shallow and irregular breathing
digestive issues
over or under-active immune system
sensitivities to the cold
The Purpose of Hypoarousal
Evolutionarily, we have adapted this response for two reasons. First, it allows us to “play dead” in the threat of danger. If you come across a mama bear and her cubs in the woods and she feels threatened by you, she may charge at you. If you run and she catches up with you, you may faint as a result. If you do this, the bear no longer sees you as a threat and may leave you alone.
Another reason we’ve evolved this trait is to protect us from experiencing more pain and trauma than we can handle. If you are on a hike and you fall off a cliff, your hypoarousal will kick in to protect you. If the cliff isn’t very tall, you may just black out for a moment until your body knows that it’s safe again. However, if the cliff is tall, you will likely pass out, so you don’t experience the fall or the drop at the bottom. That way, if you survive, you don’t have to deal with as much fear as you would if you experienced the entire event, and you’ll be more able to get yourself out of there.
Hypoarousal and Modernity
Although hypoarousal is a smart evolutionary tactic to help us survive in the wild, it’s maladapted in a modern context. Because we’re no longer faced with bears and cliffs as often as we are faced with bills and bosses, our hypoarousal can take over at inconvenient times. For instance, if we are overwhelmed by a big project, our hypoarousal may shut us down and prevent us from being able to work on it. Or if you have to set up a meeting with your boss, your hypoarousal may prevent you from having the energy or motivation to approach them.
Even though hypoarousal may be maladapted to our contemporary landscapes, it’s important to remember that all it’s trying to do is help us. When we have this understanding, it’s much easier to be gentle with ourselves and take the proper care we need to expand our window of tolerance.
Hyperarousal
When we become hyperaroused, that means that we are sympathetic dominant. In this hyperaroused state, our sympathetic nervous system turns on to mobilize us. It propels us either toward danger to fight it off or away from danger to get away from it. Here are the traits of someone who is hyperaroused:
Traits of Hyperarousal
Mental and Emotional Traits
panic
fear
worry
irritation
anger
frustration
impulsivity
high energy
stress
aggression
anxiety
reckless behavior
Physiological Traits
fast heart rate
shallow and quick breaths
high blood pressure
high levels of cortisol and adrenaline
muscle tension
The Purpose of Hyperarousal
When asked what the purpose of the fight-or-flight response is, most people get it: it allows us to fight off a threat or run away from it. If we’re dealing with an immediate threat, this response is very useful. Whether getting chased by an animal in the woods or mugged in the street at night, the state of hyperarousal gives us the energy we need to get out of the situation alive.
In the wild, when an animal faces such a threat, and they become hyperaroused, there is something important that happens afterward. Let’s say there’s an impala in the African Savanna who was being chased by a lion but got away. Once the animal is safe, it shakes the access energy off—literally. It violently moves its body to discharge all of the energy the hyperarousal built up. Other animals do this, too. Squirrels and birds will call and make noises, lots of animals run it off, and so on. Even our dogs do this—they shake, bark, and run to get out that extra energy when they’re feeling stressed.
Humans need to do this, too. In every indigenous culture around the world, there are cultural practices that aid in that energy discharge. Whether it’s through singing, dancing, chanting, or drumming, these cultural practices are important to releasing energy, leaving hyperarousal, and entering back into the window of tolerance.
Hyperarousal and Modernity
Hyperarousal is difficult to avoid in today’s world, and that’s for a couple of reasons. First, the stressors we face today are less imminent and more long-term. Instead of being chased by animals, we have to consistently perform well at work, make sure to pay dozens of bills on time and figure out how to pay back medical debt. Our bodies are not designed to deal with this kind of stress. Therefore, our hyperarousal turns on to protect us when we’re faced with stress, but there’s nothing to fight or run away from. When this happens, it’s easy to get stuck in a state of hyperarousal. In this situation, the stress response becomes frozen in our bodies because we never were able to complete the stress cycle (experience acute stress and then release the energy).
Second, at least in the United States, we’ve lost many of the cultural practices that help us discharge that hyperarousal energy. As a result, we’re stuck in states of hyperarousal and have little to no way to get that energy out.
How Large is your Window of Tolerance?
Ideally, you have a large window of tolerance, which would mean you have significant bandwidth to take in incoming stressors. However, for many people seeking psychiatric care or mental health services, this simply isn’t the case.
People who grew up in traumatic homes where they were constantly bombarded with trauma often do not have the opportunity to develop a window of tolerance (staying in a stressed state prepared for action or dulled out to experience less of it is protective when your environment is chronically traumatizing).
(Note: If you want to learn more about trauma and the nervous system, I recommend The Body Keeps the Score and Healing the Fragmented Selves of Trauma Survivors: Overcoming Internal Self-Alienation) (Bonus, both books are available through audible for auditory learners-use this link to get two free audiobooks with your premium audible trial).
Neurodivergent people, such as people with OCD, ADHD, or Autism, often have a more narrow window of tolerance. This is likely due to a combination of factors: our vulnerable neurology and sensory systems, increased rates of victimization and negative life experiences, and more.
When we experience PTSD or have a trauma-based Personality Disorder, we have a more narrow window of tolerance (again, it was adaptive at one point for your body to stay on hyper-alert, and it takes a lot of safety and new opportunities to re-wire a new narrative for the body!).
So, if you feel like you become more easily stressed and panicked than your friends, colleagues, and co-workers, it may be based in your nervous system and not due to something you have conscious control over. It can be helpful to understand this as I find for many people, it helps them to have more self-compassion. Our window of tolerance is also something that can be improved and expanded with intentional practice and work.
Nervous System Check-Ins
If you are looking to monitor and expand your window of tolerance, I recommend doing consistent nervous system check-ins and learning how to map your nervous system. Observation is the best tool we can use to learn about and expand our capacity. When we do check-ins consistently over time, we get to notice patterns that can help us heal and grow. When we can map where we are in our nervous system we have more agency to intervene.
For example, when I am able to identify that my heart rate is speeding up and that I am experiencing agitated, anxious energy, I know I am entering my hyper-aroused state. At this point, I take a few cleansing breaths and perhaps pace to move some of the excess energy through. I take steps to down-regulate my nervous system to help me get back into my window of tolerance. Or when I am getting foggy and disconnected, I may choose to go outside for a fast-paced walk in the crisp air, which is an upregulating activity.
When you are first learning to map your nervous system I recommend doing check-ins regularly. At least once or twice per day for at least a month. When you do them, take a breath, scan your body, and take note of your mental, emotional, and physiological experiences. Then, compare them to the traits listed above. Which traits under the hypoarousal list are you experiencing? What about the hyperarousal traits? Are you experiencing one more than the other? You can do this at set times each day, when you’re at a certain location, or while you’re doing certain activities. To learn more about nervous system mapping and for fillable worksheets to aid in the process, you can check out my nervous system workbook here.
Another way you can monitor your window of tolerance is by tracking your heart-rate variability (HRV). (You can learn more about heart rate variability here). The higher our HRV, the better we can adapt to life’s challenges. Therefore, the higher our HRV, the wider our window of tolerance is. You can track your HRV using an Apple Watch or a FitBit.
Summary: Hypoarousal and Hyperarousal
When we are present, grounded, and engaged, we are in our window of tolerance. However, if we encounter more stress than we can handle, we leave the window of tolerance and become dysregulated. In a state of dysregulation, we can become either hypoaroused (shutdown) or hyperaroused (mobilized). Learning about these states is an important first step to expanding our window of tolerance. By doing consistent check-ins over long periods of time, we can begin seeing patterns in our nervous system. When we understand these patterns, we can learn to give our bodies what they need to regulate themselves.
Learning about hypoarousal and hyperarousal is an important first step to expanding capacity. However, it’s only one piece of a larger puzzle. If you want more information on the nervous system and ways to regulate your body, check out this article on the nervous system. You can also get my Nervous System Workbook. In this workbook, you’ll find lots more information on the nervous system as well as a dozen worksheets to help you understand yourself and what your body needs to heal and grow.
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