Window of Tolerance

The psychiatrist Dan Siegel coined the window of tolerance to describe the zone where a nervous system handles emotion without tipping into overwhelm. Inside the window you can feel a hard feeling, name it, and choose what to do. You are activated but still online.

Push past the top edge and you go into hyperarousal: racing heart, panic, the urge to fight or flee. Drop below the bottom edge and you fall into hypoarousal: numb, foggy, shut down, going along because you have gone offline. For someone with a fawn pattern, a frown or a sharp tone can shove you out of the window fast, and appeasing is how the body scrambles back toward safety.

The window is not fixed. It widens with rest, with practice naming what you feel, and with moments where a hard feeling passed and you stayed standing. Knowing where your edges are is the start of staying inside them.