The Nervous System Curve. A map of your stress response

Most of us were never taught that our reactions under stress are not really choices, but states. We tend to think we are anxious people, or angry people, or people who go quiet and disappear. More often we are moving, without noticing, through a small set of nervous system states that every human being shares. The map below comes from polyvagal theory, the work of Stephen Porges, and it has quietly changed how many of us understand what happens in the body when life becomes too much.

Three states, one curve

Picture a curve. At the bottom, where arousal is low and we feel safe enough, is the state Porges calls ventral vagal, or social engagement. This is where we feel connected, grounded, present, open. Not free of stress, but able to feel it and still stay in contact with ourselves and the people around us.

Climb the curve, and a sense of threat comes in. The sympathetic nervous system mobilises. This is fight and flight, the body readying itself to act. Fight moves towards the threat as rage, anger, irritation, frustration. Flight moves away as panic, fear, anxiety, worry. It can feel awful, but it is not weakness. It is energy, gathered to keep you safe.

Over the top of the curve is the oldest response we have. When mobilising is not possible, or the threat feels too large to fight or flee, the system does the opposite. It shuts down. Porges calls this dorsal vagal. We might call it freeze, collapse, or going numb. Dissociation, shame, hopelessness, a sense of being trapped. The body, unable to escape, protects itself by going quiet.

The window in the middle

Between the climb and the collapse there is a line, what Dan Siegel named the window of tolerance. Below it, even when stress runs high, some part of us still feels I can. Above it, the system tips into I can’t, and the shutters come down. The window is not the same width for everyone. Early experiences, especially frightening or lonely ones, can leave it narrow, so that it takes very little to tip from coping into overwhelm. One of the quiet aims of therapy is to widen it, so that more of life stays bearable.

It is not abnormal. We just get stuck.

None of these states is a fault. We are meant to move through them. A real threat should send us up the curve. A long day should let us come back down to rest and connection. The difficulty is not the climb. It is getting stuck. Stuck in fight, always braced for the next argument. Stuck in flight, never quite able to settle. Stuck in freeze, watching life from behind glass.

When we get stuck, it is usually because, at some point, staying there kept us safe. So the work is not to judge the system, but to help it move more freely again. To climb when it genuinely needs to, and to find its way back down once the danger has passed.

Below is the curve as something you can move through. Drag the dot, or let it travel on its own, and watch how the body and the feelings change as you climb and come back down. There is no right place to be. The point is simply to notice how movement, in either direction, actually feels.

If you recognise yourself stuck somewhere on this curve, you are not broken, and you are not alone. A nervous system that learned to brace, or to disappear, learned it for good reason. In therapy we go slowly, building enough safety that the system can begin to trust there is a way down again.

There is no good zone or bad zone. Regulation is not staying calm. It is learning the way home.