The body’s stress response

The human body is designed to respond to stressful situations. Your body’s hormone control centre, called the hypothalamic-pituitary-adrenal (HPA) axis, regulates hormones including cortisol.

The HPA axis releases cortisol when a physical or psychological stressor is present to trigger your body’s defensive mechanism. This includes the fight-or-flight response, which acts on multiple systems inside you.

Typically, your body signals the HPA axis to stop releasing cortisol when the stressor is dealt with and your stress response can safely end. 

However, chronic or extreme stress can lead to disruptions in the HPA axis that impair your body’s ability to return to a calm state.

Trauma, especially when it is severe or prolonged, can cause your body to remain stuck in defence mode. This results in symptoms like:

• Increased heart rate, blood pressure, hormone levels, and inflammation
• Increased threat detection, including being jumpy, easily startled, or on edge
• Feeling hypervigilant or needing to scan your environment for danger
• Irritability
• Difficulty relaxing or falling asleep
• Shaking or crying
• Feelings of restlessness, tingling, or numbness

The Window of Tolerance

The Window of Tolerance is the optimal zone of arousal in which you can function and cope most effectively. Every person’s window is different.

When you are within your own Window of Tolerance, you can:

• Think more clearly
• Process information better
• Concentrate better
• Make more informed decisions

Chronic stress or trauma can make your window become much narrower, meaning it becomes easier for you to get pushed into a state of over-arousal or under-arousal.

Survival responses

Hyperarousal

Over-arousal, also known as hyperarousal, activates the body’s fight-or-flight response to stress. This involves aggression, shortness of breath, increased heart rate, and increased shakiness or muscle tension.

Hyperaroused responses include:

• Cry for help: When your body detects a threatening situation and instinctively becomes prepared to defend itself
• Fight: When you’re angry or irritated and you engage in impulsive and/or aggressive behaviours
• Flight: When you feel denial or anxiety. This stress may cause you to evade, omit, or sabotage to escape a stressful situation

Hypoarousal

Under-arousal, also known as hypoarousal, can involve feeling numb or withdrawn from your surroundings, feeling detached from your body or environment or as though things around you aren’t real, or feeling not in control of your body’s movements.

Hypoaroused responses include:

• Freeze: This involves feeling emotionally detached or withdrawn from your environment
• Submit: This involves surrendering to the consequences of a stressful situation when your body feels too overwhelmed to fight or flee

Dissociation

Dissociation is a disconnection or detachment between your active mind and your thoughts, memories, feelings, actions, or sense of self. It most often occurs during a state of under-arousal. 

Dissociation is a way that your body copes with overwhelming thoughts, feelings, or memories — either by shutting down, “numbing out,” or disconnecting completely from your surroundings. 

Its symptoms range from subtle to extreme. They include:

• Disengagement (not paying attention or spacing out)
• Emotional numbing
• Memory disturbances (e.g., gaps)
• Depersonalization (feeling outside of your body or as if it does not belong to you)
• Derealisation (feeling like things around you are unreal or distorted)
• Identity dissociation (feeling like a different person from yourself)

Activities

Square breathing

Connecting to your breath can help you move back inside your Window of Tolerance during times of stress.

Box breathing, also known as four-square breathing, involves inhaling to a count of four, holding air in your lungs for a count of four, exhaling at the same pace, and then holding your lungs empty for a count of four before starting over. 

It can help to visualize your breath travelling around the sides of a square while you are breathing.

Grounding 5-4-3-2-1

Use this countdown technique to mindfully take in details of your surroundings. Notice:

• Five things you can see
• Four things you can hear
• Three things you can feel
• Two things you can smell
• One thing you can taste

Try to notice small details that your mind would usually tune out, such as distant sounds or the texture of an ordinary object.

Body scan

The body scan is one of the most effective ways to begin a mindfulness meditation practice. Its purpose is to tune in to your body — i.e., to connect to your physical self — and notice without judgment any sensations you are feeling.

• Sit quietly or lie down
• Start at one end of your body and focus on each body part
• Notice any areas of tension and then try to soften or relax them
• Continue until you have mindfully scanned each part of your body

Writing prompts

1. Make a list of people, places, or things that can push you out of your Window of Tolerance. Try ranking them in order of most impactful to least. Next, write a similar list of the people, places, or things that help bring you back inside your window during times of stress.
2. The next time you notice you are feeling stressed, take a moment to write down what you’re experiencing in your body. Consider each body part. Notice where you feel tension, shakiness, or numbness. Describe the sensations in as much detail as you can.