The window of tolerance is a helpful metaphor to understand how people manage emotional intensity, especially those who have experienced trauma or who struggle with wide range of emotional arousal.
Dr. Dan Siegel introduced this concept in The Developing Mind (1999), describing it as the range of emotional arousal a person can comfortably experience, process, and integrate.
Some people naturally have a wide window of tolerance, meaning they can manage a broad range of emotions—both pleasant, like excitement/happiness and unpleasant, like shame/anger —while staying present and engaged, flexible and behave effectively. Example; Think about a woman who distracted her potential rapist by engaging him in a discussion about her sister.
Others may have a narrow window, making it harder to think clearly, behave coherently and regulate emotions, especially under stress. A flood of energy may bombard the mind and take over a number of processes, ranging from rational thinking to social behavior. At this point, emotions may flood conscious awareness. Some have called this an emotional “hijacking,” “breakdown,” or “flooding.” In such a situation, one’s behavior may no longer feel volitional, and thoughts may feel out of control. Images may fill the mind’s eye with visual representations symbolic of the emotional sensation.
When someone moves beyond their window, they may enter:
Hyperarousal (too much activation, often linked to anxiety or overwhelm)
It is when a client’s nervous system suddenly kicks into high alert, even when danger might not be present. A client may not feel in control over their actions when they enter this state. It can often be triggered by perceived threat, traumatic memories, or specific emotions. It is also one of the primary symptoms of post-traumatic stress disorder (PTSD).
Hyperarousal symptoms:
- Angry outbursts
- Fear
- Anxiety
- Emotional overwhelm
- Panic
- Hypervigilance
- Tight muscles
- “Deer in the headlights” freeze
Often, clients who experience hyperarousal are stuck “on” which can make it difficult to form healthy sleeping habits, manage emotions, and concentrate effectively. Physically, their body may seem tense and on the brink of explosion, which can eventually result in angry outbursts and hostility.
Hypoarousal (too little activation, often linked to numbness or dissociation).
Hypoarousal is also known as the “shutdown” or “collapse” response. Like hyperarousal, it can often be triggered by feeling threatened, recounting traumatic memories, or feeling emotions associated with past trauma. Even a perceived threat can be enough to send a client into shutdown or even dissociation.
Hypoarousal Symptoms:
- Depression
- Numbness
- Emptiness
- Flaccid body
- Blank stare
- Inability to speak
- Dissociation
Hypoarousal is when a client has too little arousal as the result of an overloaded parasympathetic nervous system. It can impact a client’s sleep and eating habits, leaving them feeling emotionally numb, socially withdrawn, and finding it difficult to express themselves.
Because the window of tolerance isn’t fixed, factors like temperament, past experiences, social support, and physical well-being can influence its width.
Arousal States and the Nervous System
Siegel connects the window of tolerance to the autonomic nervous system, which regulates our stress responses:
- Ventral vagal system (social engagement) – Linked to feeling safe and connected, curiosity, compassionate and grounded optimal arousal).
- Sympathetic system (mobilization) – Triggers the “fight or flight” response (hyperarousal).
- Dorsal vagal system (immobilization) – Associated with shutting down or dissociating (hypoarousal).
When a person moves outside their window of tolerance, their brain shifts into survival mode. Hyperarousal can lead to intense emotions and impulsive reactions, while hypoarousal can result in numbness, disconnection, or difficulty thinking clearly.
Working with Trauma and the Window of Tolerance
For trauma survivors, therapy aims to:
- Stay within the window of tolerance when processing difficult memories. This can involve adjusting exposure to traumatic content, using grounding techniques, or shifting focus between emotions and thoughts.
- Expand the window of tolerance over time by developing emotional regulation skills. Techniques like mindfulness, breathwork, movement, and cognitive strategies can help strengthen a sense of control and resilience.
Murray & El-Leithy (2022) emphasize that trauma work should allow clients to revisit emotions from past experiences without becoming overwhelmed. Therapists can help clients recognize their emotional states and use strategies to return to a balanced place.
Hyperarousal vs. Hypoarousal
Hyperarousal (Fight-or-flight response):
- Symptoms: Anxiety, panic, anger, hypervigilance, muscle tension, emotional overwhelm.
- Clients may feel stuck in “on” mode, making it hard to relax, sleep, or focus.
- Hypoarousal (Shutdown response):
- Symptoms: Numbness, dissociation, disconnection, difficulty speaking, blank stares.
- Clients may feel emotionally and physically shut down, making engagement difficult.
Helping Clients Regulate Arousal
When a client is dysregulated, interventions should be tailored to their state:
For Hypoarousal (Bringing Energy Back Up)
- Engage with a warm, animated voice and posture.
- Encourage physical movement (e.g., changing positions, standing up).
- Use humor or light conversation to create connection.
- Ask the client to describe three things they see to help anchor them in the present.
- Gently guide breathing exercises with an emphasis on deeper inhales.
- Use cognitive scaling (e.g., “On a scale from 1-10, how present do you feel?”) to track shifts in awareness.
- Provide explicit grounding cues: “You’re here in my office, today is ____, you’re safe.”
For Hyperarousal (Bringing Energy Back Down)
- Encourage slower, deeper breathing with extended exhales.
- Shift focus to conceptual (rather than sensory) elements of an experience.
- Use distancing techniques (e.g., recalling a memory in the third person).
- Introduce soothing activities like mindfulness, guided visualization, or gentle movement.
Final Thoughts
Understanding the window of tolerance can be a powerful tool for making sense of emotional regulation, trauma responses, and healing. Whether you’re a therapist, someone on a healing journey, or just curious about how the brain and body respond to stress, expanding your awareness of these concepts can lead to greater self-compassion and resilience.
If you found this article helpful, stay tuned for my next post, where I’ll explore;
Self-regulation vs co-regulation how the nervous system influences relationships”
Let’s continue this conversation! Feel free to share your thoughts in the comments, and don’t forget to check back soon for more insights.
Until next time—stay present, stay curious, and take care.
Books & Articles
1. Siegel, D. J. (1999). The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are. Guilford Press.
- This is the foundational text where Siegel introduces the window of tolerance concept.
2. Ogden, P., Minton, K., & Pain, C. (2006). Trauma and the Body: A Sensorimotor Approach to Psychotherapy. W. W. Norton & Company.
- Explores how the window of tolerance connects to somatic (body-based) trauma therapy.
3. Porges, S. W. (2011). The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation. W. W. Norton & Company.
- Introduces polyvagal theory, explaining the autonomic nervous system’s role in trauma responses.
4. Corrigan, F. M., Fisher, J. J., & Nutt, D. J. (2010). The Neurobiology of Trauma and Dissociation: From the Intense to the Chronic. Routledge.
- Discusses ways to regulate autonomic states in trauma therapy.
5. Murray, H., & El-Leithy, S. (2022). CPTSD and the Window of Tolerance: Integrating Trauma Memories Without Overwhelm.
- A practical guide to working with the window of tolerance in therapy.
6. Van der Kolk, B. (2014). The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma. Viking.
- A widely respected book on trauma, touching on nervous system regulation and the impact of trauma on the body and mind.
Journal Articles
7. Schore, A. N. (2009). Relational trauma and the developing right brain: The neurobiology of broken attachment bonds. Annals of the New York Academy of Sciences, 1159(1), 189-203.
- Discusses how early relational trauma affects emotional regulation and the window of tolerance.
8. Levine, P. A. (1997). Waking the Tiger: Healing Trauma. North Atlantic Books.
- Explores somatic experiencing as a method for widening the window of tolerance.
