Ever had a gut feeling or took a deep breath to calm down before a big presentation? You were likely tapping into the power of your vagus nerve. This "wanderer" nerve is the highway connecting your brain to the rest of your body, and understanding it might be the key to better mental health and resilience.

What Is the Vagus Nerve?

Chronic stress has become one of the most significant health concerns of the 21st century (Piao et al., 2024). To help us navigate it, our bodies rely on a specific nerve that "wanders" from the brainstem deep into the abdomen (Breit et al., 2018). This is the vagus nerve, and it is the 10th cranial and the longest nerve in the human body. The name "Vagus" is derived from the Latin word for "wandering”. The name comes from the vagus nerve traveling from the brainstem  down through the body to touch almost every major organ (Breit et al., 2018). It acts as the primary superhighway for the parasympathetic nervous system, which is the system responsible for calming your body down after stress (Breit et al., 2018). Vagus nerve tells the heart to slow down and the lungs to breathe deeply while managing digestion and lowering inflammation in the gut (Breit et al., 2018). Furthermore, the vagus nerve branches toward the ears and throat and helps you filter out background noise to hear voices better and controls the muscles in your voice box to change your tone. 

How the Body Learns Safety

Stress occurs whenever the challenges of life feel greater than our capacity to handle them, triggering your built-in alarm system known as the fight-or-flight response (Vanderhasselt & Ottaviani, 2022). While this surge in heart rate and blood pressure is helpful for short-term survival, true balance lies in resilience. Specifically, the ability to "turn off" the alarm once the danger has passed. Humans often struggle with this transition because we tend to get stuck in loops of negative thinking, keeping our bodies in a state of high alert long after a threat has vanished. Traditionally treating chronic stress focuses on "cognitive brakes" such as talk therapy to challenge stress-provoking thoughts. However, experts are increasingly recognizing the body’s physical role in this process (Piao et al., 2024). By using methods like vagus nerve stimulation, we can possibly send a physical all-clear signal directly to the brain. Although, note that the vagus nerve stimulation does not override cognition, but modulates neural states that make regulation easier.

While we often think of the brain as the boss that gives orders, the vagus nerve actually works mostly in the opposite direction. In fact, about 80% to 90% of its signals travel from your body up to your brain (Vanderhasselt & Ottaviani, 2022). This means your heart and gut are constantly sending status reports to your brain to tell it whether you are safe or in danger (Zagon, 2001). This constant stream of information determines our brain's perception of safety through the vagus nerve. 

How well you recover from stress is known as vagal tone, and it is estimated via your heart rate variability (HRV) (Breit et al., 2018). However, vagal tone assessed via HRV reflects the influence of the vagus nerve on the heart only, and neglects its effect on the rest of the body. If you have a high vagal tone, your body can "hit the brakes" effectively, helping you to calm down and be physically healthy. Consequently, low vagal tone is often linked to feeling stuck in a state of chronic stress or anxiety (Kuznetsov, 2024). Because the vagus nerve touches so many organs, keeping it healthy can help in many areas from mood and sleep to digestion and even how your body handles inflammation.

Training Your Calm System

In everyday life, calming the body can often work faster than trying to calm the mind. One of the simplest and most established ways to strengthen this nerve is through resonance frequency breathing (Schwerdtfeger et al., 2020). By slowing your breath to about 5 or 6 breaths per minute, roughly one breath every ten seconds, you can physically nudge your heart and brain into a shared rhythm (Schwerdtfeger et al., 2020). This technique is an easy, bottom-up way to send a signal to your brain that it is time to relax.

Another easy trick is humming (Trivedi et al., 2023). Because the vagus nerve is connected to the muscles in your throat, the vibration of your vocal cords can actually stimulate the nerve. This creates a specific vibration in the body that has been shown to help lower stress (Trivedi et al., 2023). While scientists say more research is needed to see exactly how much it helps, it is a safe and accessible way to help yourself feel a bit more grounded during a busy day.

Your gut health also plays a role in this system. Scientists have discovered a brain-gut axis where your digestive system and brain talk to each other via the vagus nerve (Breit et al., 2018). For example, certain healthy bacteria in your gut can actually send calming signals up to your brain. Studies in animals have shown that when these gut bacteria are healthy, they can even help reduce feelings of depression and anxiety by using this neural highway (Breit et al., 2018).

In addition, technology is also finding new ways to help us manage stress through wearable devices. Researchers are testing small gadgets that send tiny, gentle electrical pulses to branches of the vagus nerve in the ear or the wrist (Sanchez-Perez et al., 2023). These non-invasive tools have shown to help lower blood pressure and calm the "fight or flight" response during stressful tasks. In the future, these kinds of wearables might even monitor our stress levels 24/7 and give us a little "vagal nudge" exactly when we need it!

Bottom Line…

Ultimately, the vagus nerve represents the physical substrate of the mind-body connection. To best decrease chronic stress, scientists suggest that we should combine physical and mental techniques (Vanderhasselt & Ottaviani, 2022). This is because your brain is more likely to learn how to be resilient when it receives a safety signal from the body (like slow breathing) while also challenging your stress-provoking thoughts. Using these tools together can help your nervous system to stay flexible and strong. By learning to work with your vagus nerve, you aren't just managing stress; you are literally training your body to be more resilient. So next time your heart is racing, your palms are sweating, and your stomach is knotting up, take a moment to take a few deep breaths or hum your favourite song and your friend the vagus nerve will know what to do!

Author: Zeren Kasman

References

Breit, S., Kupferberg, A., Rogler, G., & Hasler, G. (2018). Vagus nerve as modulator of the brain–gut axis in psychiatric and inflammatory disorders. Frontiers in Psychiatry, 9, Article 44. https://doi.org/10.3389/fpsyt.2018.00044

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Kuznetsov, V. (2024, November 11). What is the best way to stimulate the vagus nerve? Meditation, breathing, ice baths, humming, or VNS devices? Scientists finally have an answer. Health Science Institute. https://scienceinhealth.com/2024/11/11/best-way-to-stimulate-the-vagus-nerve/

Piao, X., Xie, J., & Managi, S. (2024). Continuous worsening of population emotional stress globally: Universality and variations. BMC Public Health, 24(1), 3576. https://doi.org/10.1186/s12889-024-20961-4

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Sanchez-Perez, J. A., Gazi, A. H., Rahman, F. N., Harrison, G. W., Gurel, N. Z., Wittbrodt, M. T., & Inan, O. T. (2023). Transcutaneous auricular vagus nerve stimulation and median nerve stimulation reduce acute stress in young healthy adults. Frontiers in Neuroscience, 17, 1213982. https://doi.org/10.3389/fnins.2023.1213982 

Schwerdtfeger, A. R., Schwarz, G., Pfurtscheller, K., Thayer, J. F., Jarczok, M. N., & Pfurtscheller, G. (2020). Heart rate variability (HRV): From brain death to resonance breathing at 6 breaths per minute. Clinical Neurophysiology, 131(3), 676–693. https://doi.org/10.1016/j.clinph.2019.11.013

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