Our nervous system has three states—and why this is crucial for our health

In traditional medical theory, the autonomic nervous system is often described as a balance between the sympathetic nervous system (“stress response”) and the parasympathetic nervous system (“relaxation”). While this model is helpful, its oversimplification leaves much to be desired.

The Polyvagal Theory, developed by Stephen Porges, expands on this understanding and demonstrates that the parasympathetic nervous system, in particular, must be viewed in a more nuanced way. It describes three clearly distinguishable states of the nervous system that influence both emotional experience and key physiological functions—from cardiovascular regulation to immune activity.

The Three States of the Nervous System

1. Ventral vagal state (safety and regulation)
This state is part of the parasympathetic nervous system—it is when the body is in balance. It represents safety, social connection, and inner stability. Simply put: you feel calm, present, and socially connected to those around you.
Physiologically, it creates optimal conditions for regeneration, healing processes, and a properly functioning immune system.

2. Sympathetic State (Activation)
The sympathetic nervous system dominates here. This state corresponds to the classic stress response. The body mobilizes energy, heart rate and alertness increase—the body is geared toward performance, fight, or flight.
In the short term, this response is useful and necessary. It becomes problematic when it persists chronically.

3. Dorsal vagal state (withdrawal and energy conservation)
This state also belongs to the parasympathetic nervous system, but differs significantly from the ventral vagal component. In the event of prolonged overload, the nervous system can shift into a state of reduced activity.
Here, the organism responds with withdrawal, reduced activity, and energy conservation. This state often manifests as exhaustion, listlessness, or inner withdrawal. This mechanism, too, originally serves a protective function, but is stressful in the long term.

When Regulation Is Lost

In everyday life, these states usually shift flexibly. It is precisely this flexibility that is crucial to good health.

However, chronic stress can impair this ability to regulate. The body then either remains in a constant state of arousal or increasingly slips into a state of exhaustion.

Common symptoms that may be associated with impaired regulation of the nervous system include:

• persistent fatigue and reduced performance
• Sleep disorders
• functional digestive problems
• increased susceptibility to stress

These symptoms are not only subjectively distressing, but also reflect physical changes. Studies show that prolonged stress:

• can promote inflammatory processes in the body
• affects hormonal balance
• hinders regeneration at the cellular level

A commonly studied marker in this context is heart rate variability (HRV). It provides insight into how flexibly the nervous system can respond to stress. Higher HRV is associated with greater adaptability and better overall health.

Practical tips for everyday life: How can we specifically regulate the nervous system?

The good news is that the nervous system is adaptable. Even though periods of stress aren’t always avoidable, we can actively support the body’s ability to regulate itself.

The point is not to eliminate stress entirely—but to repeatedly send signals of safety to the body. It is precisely these signals that help the nervous system return to balance after a prolonged state of arousal.

The following measures can help

1) Conscious breathing: Slow breaths with prolonged exhalations have a direct effect on the autonomic nervous system and can help reduce the stress response.

2) Regular breaks: Short breaks throughout the day—even just a few minutes—can help relieve stress on the nervous system. What matters is consistency, not duration.

3) Exercise as a way to manage stress: Moderate physical activity, walks, or spending time outdoors help reduce stress hormones and support the regulation of the nervous system.

4) Social connections and bonds: Positive interpersonal interactions send signals of safety to the nervous system. Social connectedness therefore plays an important role in stress regulation.

5) Recognizing warning signs early: Persistentexhaustion, sleep problems, increasing irritability, or a feeling of constant tension can be signs that the nervous system is under chronic strain. Recognizing such signals early is an important step in taking countermeasures.

6) Don’t just cope with stress—regulate it: Many people try to cope with stress through short-term distractions. However, a more sustainable approach is to strengthen your ability to regulate your own stress—that is, the ability to consciously return to a state of calm and security after experiencing stress.

These factors help maintain balance in the nervous system and can increase resilience to stress over the long term.

Conclusion

Good health does not depend solely on avoiding stress. Rather, what matters most is the nervous system’s ability to switch flexibly between arousal and recovery.

The polyvagal theory expands upon the traditional view of the sympathetic and parasympathetic nervous systems and provides a more nuanced understanding of the connections between the nervous system and health.

At the same time, it shows that the regulation of the nervous system is not a static state, but can be actively supported through conscious habits in everyday life. Even small changes can help restore balance and build long-term resilience to stress.

Sources

Fundamentals of Polyvagal Theory

• Porges, S. W. (2011). The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation. W. W. Norton & Company.
• Porges, S. W. (2007). The polyvagal perspective. Biological Psychology, 74(2), 116–143. https://doi.org/10.1016/j.biopsycho.2006.06.009

The Autonomic Nervous System, Stress, and Physiology

• McEwen, B. S. (2007). Physiology and neurobiology of stress and adaptation: the central role of the brain. Physiological Reviews, 87(3), 873–904. https://doi.org/10.1152/physrev.00041.2006
• Chrousos, G. P. (2009). Stress and disorders of the stress system. Nature Reviews Endocrinology, 5, 374–381. https://doi.org/10.1038/nrendo.2009.106

Stress, Inflammation, and Hormonal Regulation

• Slavich, G. M., & Irwin, M. R. (2014). From stress to inflammation and major depression. Psychological Bulletin, 140(3), 774–815. https://doi.org/10.1037/a0035302
• Black, P. H., & Garbutt, L. D. (2002). Stress, inflammation, and cardiovascular disease. Journal of Psychosomatic Research, 52(1), 1–23. https://doi.org/10.1016/S0022-3999(01)00302-6

Heart Rate Variability (HRV)

• Shaffer, F., & Ginsberg, J. P. (2017). An overview of heart rate variability metrics and norms. Frontiers in Public Health, 5, 258. https://doi.org/10.3389/fpubh.2017.00258
• Thayer, J. F., & Lane, R. D. (2000). A model of neurovisceral integration. Biological Psychology, 74(2), 116–143. https://doi.org/10.1016/S0301-0511(00)00023-0