The Vagus Nerve

TLDR:

The vagus nerve is having its moment in pop culture, and I am happy about that. It is one of the most important yet often overlooked parts of our nervous system. Many scientific studies show it plays a crucial role in regulating many bodily functions and has a significant impact on our overall health and brain function. For those of us feeling stressed or overwhelmed, understanding how this nerve works and how to tone it can offer practical ways to improve well-being.

What Is the Vagus Nerve and Where Is It Located?

The vagus nerve is the longest and one of the 12 cranial (aka your skull) nerves (CN) in the body. Nerd alert: It is also known as CN X; as it is the 10th cranial nerve, and as they are classified with Roman numerals, where 10 = X.

It starts in the brainstem, specifically the medulla oblongata, and extends down through the neck into the chest and abdomen. This nerve connects the brain to multiple organs including the heart, lungs, digestive tract, and more. In fact, there are "two sides" of the vagus nerve. They can be interpreted in two main ways: the two physical nerves (right and left) and the two functional sides described by polyvagal theory (dorsal and ventral) (Porges, 2011). The right and left vagus nerves are paired, running down the respective sides of the body from the brain to the abdomen, while the dorsal (back) and ventral (front) sides refer to functional branches that regulate different nervous system responses, such as social engagement versus shutdown.

Because it interfaces with so many systems, the vagus nerve acts as a communication superhighway between the brain and body. It helps regulate heart rate, breathing, digestion, and even immune responses. This wide-reaching influence is why it is sometimes called the “wandering nerve” (vagus means wandering in Latin).

Path of the Vagus Nerve. The image shows the path of the vagus nerve (and a section of the facial nerve). Source: Kenny, 2002.

Why the Vagus Nerve Is Vital for Our Health

The vagus nerve is a key player in the parasympathetic nervous system, which controls the “rest and digest” functions. When activated, it slows the heart rate, lowers blood pressure, and promotes digestion and relaxation. This contrasts with the sympathetic nervous system, which triggers the “fight or flight” response. This makes sense, because whenever I get stressed or anxious, I get stomach ache, I cannot eat, and it just feels off.

A well-functioning vagus nerve helps maintain balance in the body, reducing stress and inflammation. Chronic stress can impair vagal tone, which is the nerve’s ability to regulate bodily functions effectively. Low vagal tone is also linked to anxiety, depression, digestive issues, and even heart disease (Thayer & Sternberg, 2006).

How the Vagus Nerve Affects Brain Function

The vagus nerve also influences your brain health. It sends sensory information from the body to the brain and helps regulate neurotransmitters like acetylcholine and gamma-aminobutyric acid (GABA), which affect mood and cognition.

Research shows that stimulating the vagus nerve can improve symptoms of depression. For example, vagus nerve stimulation (VNS) therapy, which uses electrical impulses to activate the nerve, has been approved for treatment-resistant depression and epilepsy (Nemeroff et al., 2006).

Moreover, vagal activity supports neuroplasticity, the brain’s ability to adapt and form new connections. This is essential for learning, memory, and recovery from brain injuries (Breit, Kupferberg, Rogler, & Hasler, 2018).

Scientific Evidence on Toning the Vagus Nerve

Toning the vagus nerve means improving its function and responsiveness. Just like toning your muscles for strength and skeletal support, you can tone this nerve. Several studies have explored natural ways to do this and their effects on health.

• Deep Breathing and Slow Exhalation: Slow, deep breathing activates the vagus nerve and increases heart rate variability (HRV), a marker of good vagal tone. It is through my breathing and meditation practice that I first learnt about the vagus nerve. A study by Lehrer et al. (2003) found that paced breathing (or what I call balanced breathing) at around six breaths per minute improved HRV and reduced anxiety.

  
  

• Cold Exposure: Brief exposure to cold, such as cold showers, or splashing cold water on the face, stimulates the vagus nerve. Even more effective if you can put cold water on your neck, where a lot of the nerve is connected. Jungmann et al. (2018) suggests that cold stimulation in the right lateral (side) neck region has the potential as an effective alternative VNS therapy. This is why you often see in movies, someone splashing cold water on their face before an important meeting. This is not for everyone, and can be too intense if you are in a very anxious state. Like anything you want to start small and simple, and not dive head first into icy water for 30 minutes.

  
  

• Meditation and Mindfulness: Mindfulness practices increase vagal tone by promoting relaxation and reducing stress. A study by Ditto, Eclache, and Goldman (2006) demonstrated that even brief mindfulness meditation improved HRV and mood. Breit et al (2018) also found that self-generated positive emotions via loving-kindness meditation lead to an increase in positive emotions, which in turn produced increases in vagal tone.

  
  

• Exercise: Regular physical activity enhances vagal tone and cardiovascular health. A meta-analysis by Routledge et al. (2010) confirmed that aerobic exercise increases HRV and vagal activity.

  
  

• Social Connection: Positive social interactions stimulate the vagus nerve, promoting feelings of safety and calm. Porges (2011) proposed the Polyvagal Theory, which links social engagement to vagal function.

  
  

Practical Ways to Support Your Vagus Nerve

For those feeling stressed, incorporating simple habits to tone the vagus nerve can make a difference:

• Practice slow, deep 'belly' breathing daily, focusing on longer exhales. Use the 'ocean' breath - where you constrict the glottis at the back of the throat to make a 'shhh' sound when breathing.

• Try cold water on your face or neck for a few seconds.

• Engage in mindfulness or meditation for at least 10 minutes.

• Humming, singing or chanting can stimulate the vagus nerve, similar to VNS therapies.

• Stay physically active with aerobic exercises like walking or cycling.

• Foster social connections and spend time with supportive people.

  
  

These practices can improve your body's ability to manage stress and support brain health over time.

Person practicing deep breathing or meditation in nature, during the day with the sun shining and sitting on the grass.

The Takeaway on the Vagus Nerve and Your Well-being

The vagus nerve plays a central role in how our body and brain respond to stress and maintain health. Scientific studies show that improving vagal tone through breathing, cold exposure, meditation, exercise, and social connection can reduce anxiety, improve mood, and support brain function.

If you feel overwhelmed or stressed, focusing on simple ways to support your vagus nerve can be a practical step toward better health. These methods are accessible, backed by research, and can fit into daily life.

Remember, this information is for educational purposes and not a substitute for medical advice. If you have health concerns, consult a healthcare professional.

References

Kenny, B, J., Bordoni, B. (2022, Nov 7). Neuroanatomy, Cranial Nerve 10 (Vagus Nerve). Treasure Island (FL): Stat Pearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK537171/

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, 44. https://doi.org/10.3389/fpsyt.2018.00044

Ditto, B., Eclache, M., & Goldman, N. (2006). Short-term autonomic and cardiovascular effects of mindfulness body scan meditation. Annals of Behavioral Medicine, 32(3), 227–234. https://doi.org/10.1207/s15324796abm3203_7

Lehrer, P. M., Vaschillo, E., & Vaschillo, B. (2003). Resonant frequency biofeedback training to increase cardiac variability: Rationale and manual for training. Applied Psychophysiology and Biofeedback, 28(3), 203–215. https://doi.org/10.1023/A:1025754825745

Nemeroff, C. B., Mayberg, H. S., Krahl, S. E., McNamara, J., Frazer, A., Henry, T. R., ... & George, M. S. (2006). Vagus nerve stimulation therapy in treatment-resistant depression: clinical evidence and putative neurobiological mechanisms. Neuropsychopharmacology, 31(7), 1345–1355. https://doi.org/10.1038/sj.npp.1301082

Porges, S. W. (2011). The polyvagal theory: Neurophysiological foundations of emotions, attachment, communication, and self-regulation. Norton Series on Interpersonal Neurobiology. W. W. Norton & Company.

Jungmann M, Vencatachellum S, Van Ryckeghem D, Vögele C. (2018, Oct 9). Effects of Cold Stimulation on Cardiac-Vagal Activation in Healthy Participants: Randomized Controlled Trial. JMIR Form Res. 2(2): e10257. https://doi.org/10.2196/10257.