Hyperarousal and Hypoarousal

Psychological State

The two states outside the window of tolerance — hyperarousal is too much activation (fight, flight, flooding), hypoarousal is too little (numbness, freeze, shutdown).

Also known as: hyperarousal, hypoarousal, over-arousal, under-arousal

Hyperarousal and hypoarousal are the two ways your nervous system can move outside the window of tolerance — either by activating too much or by shutting down too much. Both are protective responses. Neither is a failure. Recognizing which one you are in determines which tools will actually help in the moment.

Hyperarousal is the nervous system’s accelerator. Common experiences include racing thoughts, rapid heartbeat, shallow breathing, tight chest or stomach, restlessness, irritability, hypervigilance, urge to escape, and emotional flooding. It’s often the fight-or-flight state turned up loud. It feels like too much — the system is doing everything it can to handle a threat.

Hypoarousal is the nervous system’s brake, applied hard. Common experiences include numbness, foggy thinking, heaviness, dissociation (feeling unreal or outside yourself), emotional flatness, disconnection from body sensation, and the sense of being stuck underwater. It feels like not enough — the system has concluded the threat is too big to fight or flee, so it pulls back from engagement altogether.

Why the distinction matters

The tools that help in each state are almost opposite.

  • Hyperarousal responds to slowing down. Slow exhales, box breathing, cold water on the face, feet firmly on the floor, soft lighting, calm place visualization — anything that tells the nervous system “we are safe, we can settle.”
  • Hypoarousal responds to gentle activation. Orienting to your surroundings (naming five things you can see), light movement, standing up, 5-4-3-2-1 grounding, firmer physical input (a cool drink, a textured object in your hand) — anything that reconnects you to body and environment.

The common mistake is using a hyperarousal tool during hypoarousal (slow breathing when you’re already shut down tends to deepen the shutdown) or vice versa. Noticing which state you’re in first, then choosing the tool, is the practice.