Your Nervous System and the Window of Tolerance

Have you ever wondered why some days you can handle stress with ease, while other days the smallest thing can send you spiralling?

The answer often lies in your nervous system—and in what’s called your window of tolerance.

Understanding how your brain and body work together gives you powerful tools to regulate your emotions, respond to stress, and feel more grounded in daily life.

Meet Your Nervous System

Your nervous system is your body’s command centre. It includes your brain, spinal cord, and the network of nerves that reach every part of you. It manages everything—from thoughts and movements to automatic processes like breathing and digestion. Just as importantly, it also shapes how you experience emotions.

A simple way to understand the brain is to think about it in three parts:

1. Brainstem – controls survival basics like breathing and heart rate.

2. Limbic system – your emotional centre; it drives the fight, flight, freeze, or appease response.

3. Cortex – your “thinking brain,” responsible for reasoning, problem-solving, and managing big emotions.

When all three work together, you feel safe, connected, and able to handle challenges. This balanced state is what we call the window of tolerance.

What Is the Window of Tolerance?

The window of tolerance is the optimal zone of nervous system arousal. Inside this window, your brain processes information smoothly without getting overwhelmed. You feel calm yet alert, grounded yet energised. You can connect with others, make thoughtful decisions, and ride the natural waves of stress without losing your balance.

This state is supported by your parasympathetic nervous system—also known as rest and digest.

What Happens When You Leave the Window?

Sometimes, stress or perceived danger pushes us outside our window. When this happens, the limbic system takes over and sends the cortex offline. This triggers the fight, flight, freeze, or appease response—an ancient survival mechanism that kept our ancestors safe.

• Hyperarousal (fight/flight): Your body speeds up. Heart rate and breathing increase, muscles tense, pupils dilate. You might feel anxious, panicked, angry, or out of control.

• Hypoarousal (freeze/appease): Your body slows down. Breathing and heart rate drop, energy drains, and you may feel numb, disconnected, or immobilised.

These responses are useful in real danger (like slamming on the brakes to avoid a car accident). But in modern life, our nervous system often reacts to non-life-threatening stressors—like deadlines, arguments, or meeting new people—as if they were survival threats.

Why Some People React More Strongly

Your window of tolerance isn’t fixed—it can widen or narrow depending on your life experiences, current stress levels, sleep, and even hunger.

• Trauma and chronic stress can shrink your window, making your nervous system quicker to sound the alarm.

• Everyday factors—like being tired, hungry, or in pain—also narrow your window.

• On the flip side, rest, connection, and healthy coping strategies can expand it.

Expanding Your Window

The good news? You can grow your capacity to stay regulated. Here are some ways:

• Know your nervous system. Notice how your body feels when you’re calm, and how it shifts when stress kicks in.

• Care for basics. Sleep, nutrition, and movement create a stronger foundation for regulation.

• Practice mindfulness & self-compassion. These help train the cortex to stay online when emotions surge.

• Build connection. Safe relationships are powerful regulators for the nervous system.

• Work with a professional. Therapy can help process trauma and widen your window over time.

Coming Back Into Your Window

When you do get thrown outside your window, different strategies can bring you back:

• If you’re in fight/flight (hyperarousal): Release energy first (walk, shake, dance, run stairs), then soothe (deep breathing, grounding, stretching, weighted blanket, tea, calming music).

• If you’re in freeze/appease (hypoarousal): Add energy (stand tall, stomp feet, listen to upbeat music, take a brisk walk, rub arms and legs).

Other helpful tools: cold water, journaling, creative outlets, or simply naming your emotions.

And don’t forget co-regulation—seeking comfort with others. A hug, talking with a trusted friend, or even cuddling your pet can bring your nervous system back into balance.

Final Thoughts

Your nervous system is constantly working to keep you safe. Sometimes it overreacts, but with awareness and practice, you can learn to regulate it, expand your window of tolerance, and feel more calm, connected, and resilient in the face of stress.

✨ Start by noticing your patterns this week. Where are you in your window—and what helps bring you back?