One of the most helpful concepts I introduce to my clients early in the trauma healing process is the Window of Tolerance. Understanding this concept often brings a sense of relief and validation to people who’ve spent years feeling overwhelmed, checked out, or confused by the intensity of their emotional responses. If you’ve ever wondered, “Why do I go from feeling fine to spiraling in seconds?” or “Why do I feel numb and disconnected for hours or days at a time?” — you’re not alone. The Window of Tolerance might offer some answers.
Understanding the Window of Tolerance is foundational to trauma healing. It provides a compassionate framework for why we might react the way we do and how we can support ourselves in responding differently over time.
What Is the Window of Tolerance?
Coined by Dr. Dan Siegel, the Window of Tolerance refers to the optimal zone of arousal in which we are able to function and respond to the demands of life in a flexible, adaptive way. When we’re within our window, we can think clearly, feel our emotions without being overwhelmed by them, and connect with others. Our nervous system is regulated, and we feel a sense of internal safety and balance.
Outside of this window, things can quickly feel unmanageable. We may move into hyperarousal, known as a state of anxiety, panic, anger, or overwhelm. Or we may slide into hypoarousal, characterized by a shutdown state marked by numbness, fatigue, dissociation, or depression. In either direction, our brain and body are saying, “I don’t feel safe.” Someone who has unresolved trauma may feel that their window is narrow; this is because they have had a history of overwhelming and unsafe experiences and have not had the opportunity to tend to the unmet needs caused by the trauma.
The Window of Tolerance Is Not Fixed
Here’s the good news: your Window of Tolerance is not fixed. It can grow and shift over time.
Many people assume their capacity to handle stress or emotion is simply “who they are.” They might say, “I’ve always been anxious,” or “I’m just not an emotional person.” But what I often help clients explore is that these patterns are adaptive responses to their environment, not permanent personality traits. When we’ve lived through trauma, our nervous system becomes more reactive in an effort to protect us. It becomes highly sensitive to cues of danger, even when those cues are no longer relevant in the present moment.
With time, support, and practice, we can teach the nervous system that it’s safe to expand its capacity. This happens through grounding, mindfulness, somatic regulation techniques, and, importantly, experiences of safe connection. Our window can widen, making space for more emotional range without overwhelm or shutdown.
It’s also important to understand that life changes can naturally stretch or shrink our window, even after we’ve done significant healing. Times of grief, transition, burnout, illness, or high stress can temporarily narrow the window and that’s not a failure. It’s simply your system asking for more care, more rest, or more support.
How and When We’re Pushed Out of the Window
One of the most common things I hear from clients is: “I was doing fine, and then suddenly I wasn’t.”
The stressors that push us out of our window differ person-to-person. It may be work stress, it may be a fight with a family member, it might be a sensory reminder of a traumatic event, or even a combination of different events. When we’re pushed out of our window of tolerance, the shift can be fast and intense. We often burn hot and bright; moving into hyperarousal where everything feels urgent, emotional, and intense. This might look like panic, rage, racing thoughts, restlessness, or a strong fight-or-flight response. You might feel like your body is on fire, like you have to act now or escape immediately.
For others, the overwhelm might send them in the opposite direction into hypoarousal. This can feel like going numb, shutting down, zoning out, or feeling like you’re not even in your own body. It’s as if your system hit the emergency brakes, and now you’re frozen in place.
What often follows either state is exhaustion. Burning hot or shutting down takes a tremendous toll on your body and mind. Once the surge has passed, many people find themselves needing long periods of rest, feeling drained, emotionally flat, or even ashamed of how they reacted. This is where a trauma-informed lens is crucial as it reminds us that these are not character flaws, but survival responses from a nervous system doing its best to protect us.
Supporting Yourself Back Into the Window
When we notice we’re outside of our window, the goal isn’t to shame or fix ourselves, but rather to gently guide the system back to regulation. Grounding techniques, breathwork, movement, co-regulation with another person, or increasing compassionate awareness are all techniques that can help us return to our window. I understand that it can be difficult to remember to utilize any of these techniques when you are either in hyper or hypoarousal. That is why it is important to practice these skills even when you’re feeling regulated and in your window; you need to give your mind and body practice and cues to put these techniques into effect. This is something you can do in your therapy session to figure out which technique works best for you.
What to take away
The Window of Tolerance reminds us that healing isn’t about being “calm all the time” — it’s about being able to return to a place of balance with more ease. It’s about giving ourselves grace when life is hard, and building trust in our own capacity to recover.
If you’re working to understand your nervous system and heal from trauma, know that you’re not broken. You’re human — and your body is doing everything it can to keep you safe. With time, patience, and support, that window can expand. You don’t have to live outside of it forever.