Connecting Cellular Danger Response and the Vagus Nerve

Dr. Susan Monias
Jul 14
4 min read

We have been talking about the vagus nerve here at Dr. Susan Monias for some time, but many people still do not fully understand its importance.

I began creating a mini-course on it, and I might still do that. Until then, I’ll tell you that personally, improving my vagal tone has been life-changing. Many of my patients who have been diligent in improving their vagal tone have experienced significant benefits.

To make this easier for everyone, I recommend the TRUVAGA device. I have no affiliation with the company; it is simply the device I personally used, and I found the price point reasonable. The device costs about $250 and only requires 2–4 minutes of use per day.

It is no secret that one of the leading contributors to my MS diagnosis was extreme stress in my life. This is why this information is so important today. Nearly everyone is under enormous stress, whether physical, emotional, or chemical.

Our modern world places constant stress on our bodies. This ties back to my “20 Things” PDF, available in my course or on my website. People did not experience these same stressors 150 years ago.

Plus, many of the habits I discuss in my Circle of Prevention were naturally built into everyday life rather than things we now have to intentionally make time for.

Think about it as we connect the Cell Danger Response (CDR) to the vagus nerve.

Your Vagus Nerve and CDR

I have taught about cellular inflammation for the past 10 years, and much of this information was introduced to me by my mentor, Dr. Daniel Pompa. However, I want to take this conversation one step further.

I will always continue focusing on cellular inflammation, but this deeper understanding has had a profound impact on my own life and health journey, including my MS (autoimmune) diagnosis.

The vagus nerve helps regulate:

Inflammation
Stress responses
Immune signaling
The body’s ability to return to a state of safety and healing

What Is the Vagus Nerve?

The vagus nerve is the main communication highway between the:

Brain
Heart
Lungs
Digestive system
Immune system

A Healthy Vagus Nerve

A healthy vagus nerve helps the body:

Calm inflammation
Regulate stress
Improve digestion
Balance immune responses
Slow heart rate
Support recovery and healing

It is the major nerve of the parasympathetic nervous system, often referred to as the:

“Rest, digest, heal, and repair” system.

How it connects to the Cell Danger Response

The CDR is essentially a survival state. When cells detect danger, the body shifts into:

Protection mode
Inflammation
Hypervigilance
Immune activation

At the same time, the nervous system shifts toward:

Sympathetic dominance (“fight or flight”)
Reduced parasympathetic activity
Decreased vagal tone

This matters because the vagus nerve signals the body that the danger has passed and that it is safe to relax again.

If vagal signaling becomes weak or dysregulated,

The body may struggle to fully shut down the inflammatory response.

The inflammatory reflex

One major connection is the cholinergic anti-inflammatory pathway.

The vagus nerve helps regulate immune cells and inflammatory cytokines. When functioning properly, the vagus nerve can help reduce excessive inflammation. Researchers refer to this as the inflammatory reflex.

In simple terms:

The immune system creates inflammation → the vagus nerve detects it → the brain responds → calming signals are sent back to reduce inflammation.

If this loop becomes impaired:

Inflammation may remain elevated
Immune dysregulation may persist
The body can remain stuck in “danger mode”

Chronic stress is the issue today

Stress comes from many sources:

Traffic
Overworking
Mold exposure
Excessive exercise
Chemical exposure
Emotional situations
Poor diet and processed foods

For me personally, emotional stress played a major role. Repetitive thoughts and prolonged physiological stress, combined with gut issues and the rise of processed foods, additives, preservatives, colors, and dyes, all contributed to the problem.

My mom raised us with a very natural lifestyle, no junk food or snacks in the house. So, at 12 years old, I started babysitting and used my own money to buy candy from the local store!

The point is: stress is everywhere: in our thoughts, emotions, work, school, relationships, schedules, and environment. No one is immune to the stressors of modern life.

Chronic stress affects both the vagal tone and the Cell Danger Response,

making it more difficult for the body to repair, heal, and maintain immune balance.

Symptoms Associated with Poor Vagal Tone

Digestive issues

Bloating

Constipation

Anxiety

Elevated heart rate

Fatigue

Dizziness

Poor stress tolerance

Sleep disruption

Increased inflammatory responses

How to improve vagal tone

You can visit TRUVAGA.com to learn more about the device, or you can begin practicing simple techniques every day, such as deep breathing, where you inhale for a count of four and exhale for a count of six. This and these other supportive practices signal safety to the nervous system: