The Window of Tolerance
The window of tolerance is a concept developed by Daniel Siegel that describes the zone of arousal within which a person can function effectively. Within this window, we can think clearly, feel our emotions without being overwhelmed, and respond flexibly to life's demands.
The Three Zones
Inside the window: Can think clearly. Feel emotions without being overwhelmed. Respond flexibly. Process experiences. Relate to others.
Above the window (hyperarousal): Overwhelmed, anxious, panicked. Fight or flight activated. Can't think clearly. Emotionally flooded. Hypervigilant.
Below the window (hypoarousal): Shut down, numb, disconnected. Depressed, collapsed. No energy. Dissociated. Can't feel.
How Trauma Affects the Window
Trauma narrows the window of tolerance and makes it harder to stay inside. Trauma survivors often exist outside this window, either too activated or too shut down. They're easily pushed out into either hyperarousal or hypoarousal.
The width of the window of tolerance varies from person to person and can be affected by:
- Early attachment experiences
- History of trauma
- Current life circumstances
- Physical health
- Sleep and nutrition
- Social support
For some people, the window is quite narrow: they may flip quickly from overwhelm to shutdown, with little capacity to stay present with challenging experiences. For others, the window is wider: they can tolerate significant stress while remaining functional and connected.
The Goal of Healing
The goal of nervous system regulation is not to stay in a narrow band of calm neutrality but to expand the window of tolerance: to be able to experience a wider range of states while maintaining the capacity to return to equilibrium.
Gradually widening the window of tolerance means you can handle more activation without being overwhelmed, and access more aliveness without shutting down.
TRE and the Window of Tolerance
TRE works directly with the window of tolerance. The tremor mechanism helps discharge accumulated stress and tension, naturally bringing the nervous system back toward equilibrium. Over time, regular practice can help expand the window, building greater capacity for regulation.
The key insight is that TRE is not about achieving maximum release or the most intense tremors. It is about working within your window of tolerance, giving your nervous system the experience of activation followed by successful return to baseline.
This is how we build regulatory capacity over time. The nervous system learns from experience. When we repeatedly experience mild activation followed by successful return to calm, the system learns that activation is survivable and that it can self-regulate. This gradually expands what we can tolerate.
If TRE practice takes you outside your window of tolerance – into overwhelm or dissociation – it can actually be counterproductive. The nervous system learns from experience, and repeated experiences of dysregulation do not build capacity. Self-regulation is therefore not optional but essential.
Signs You're Outside Your Window
Signs of hyperarousal (above the window):
- Racing heart
- Rapid, shallow breathing
- Feeling panicky or overwhelmed
- Unable to think clearly
- Wanting to flee or escape
- Intense emotions that feel uncontrollable
Signs of hypoarousal (below the window):
- Feeling spacey or far away
- Numbness or disconnection
- Difficulty feeling emotions
- Brain fog, can't think
- Feeling collapsed or hopeless
- Dissociation
If you notice these signs during TRE, use self-regulation techniques to return to your window.