The Window of Tolerance: Why Some Days Feel Like Too Much — or Nothing at All

Have you ever had a day where you woke up and everything felt impossible — the noise, the emails, the simplest decisions? And then another day where you felt completely flat, numb, disconnected — like you were watching your own life through glass?

If you’ve experienced trauma, this is likely familiar. And it has a name: dysregulation outside the window of tolerance.

What Is the Window of Tolerance?

Developed by psychiatrist and neurobiologist Dan Siegel, the window of tolerance refers to the optimal zone of nervous system arousal — where we have access to our full cognitive and emotional capacities. Inside the window, we can think clearly, feel our feelings without being overwhelmed by them, connect with others, and function effectively.

Trauma narrows this window. What once fell within your capacity to handle may now tip you outside of it — into either hyperarousal (too much) or hypoarousal (too little).

Hyperarousal: When It’s Too Much

Hyperarousal is the state of being flooded — too activated, too much. It shows up as anxiety, panic, irritability, hypervigilance, racing thoughts, difficulty sleeping, feeling constantly “on edge.” This is the nervous system stuck in high alert, unable to come down even when the threat has passed.

Hypoarousal: When You Feel Nothing

Hypoarousal is the opposite state — shutdown, disconnection, numbness. You might feel foggy, detached, empty, or like you can’t find the energy to care about anything. This is the nervous system’s collapse response — a deep-body shutdown that protected you when fight or flight wasn’t possible.

Both states are trauma responses. Neither means you are broken.

Expanding the Window

One of the central goals of trauma therapy is to gradually expand the window of tolerance — to build the nervous system’s capacity to stay present, engaged and regulated even when things feel hard. This isn’t about becoming someone who never struggles. It’s about developing a wider range of what you can handle without tipping into survival mode.

Skills drawn from DBT (distress tolerance and emotional regulation), mindfulness, and somatic approaches help build this capacity over time. So does the experience of a consistently safe, supportive therapeutic relationship — which in itself is a form of nervous system regulation.

Trauma Support in Brampton and Ontario

At ChngeWrks, we work with people who are living with the effects of trauma — including chronic dysregulation, emotional overwhelm and disconnection. Book a free consultation today. Virtual sessions available across Ontario.

References & Further Reading

• Siegel, D. J. (1999). The Developing Mind. Guilford Press.
• van der Kolk, B. (2014). The Body Keeps the Score. Viking.
• Ogden, P., Minton, K., & Pain, C. (2006). Trauma and the Body. W. W. Norton.
• Linehan, M. M. (1993). Cognitive-Behavioral Treatment of Borderline Personality Disorder. Guilford Press.