What Happens in Vagus, Definitely Does Not Stay in Vagus
- Feb 25, 2025
- 5 min read
Dr. Keelin Regan-Reed, PT, DPT, is often referred to as the "Nerve Whisperer" by her clients and has been called a "Human MRI" by her peers. She is an Orthopedic and Neural Manual Physical Therapist specializing in Neural Manipulation and the published author of Fix It Yourself! A Self Help Guide To Treating Common Muscular Aches And Pains.
You might have heard the phrase, “What happens in Vegas, stays in Vegas!” While that may be true when traveling to Las Vegas, Nevada, it does not apply when it comes to understanding our 10th cranial nerve.
Complete guide to understanding our 10th cranial nerve: The vagus nerve
The vagus nerve is our 10th cranial nerve (CNX) and is recognized as the longest cranial nerve in the body. It originates in the brainstem and runs down the lateral side of the neck, through the thorax (chest), and into the abdominal cavity, where it branches extensively throughout the abdominal viscera. It contributes to the innervation of all our organs, starting with a small branch to the thyroid gland in the neck and extending all the way to the colon and urogenital organs in the pelvic cavity.
In addition to transmitting signals to various organs, the vagus nerve is composed of 80% to 90% sensory fibers, which convey information about the state of the body's organs back to the brain. This means it does not just send information to organs but primarily receives information from them and relays it back to Grand Central Station, aka the brain.
The vagus nerve is the Chief Operating Officer of the body, serving as the primary communication highway that connects the brain to our organs and regulates their function.
Have you ever missed a meeting because you didn’t get the memo? Or arrived late to an appointment because your alarm clock didn’t go off at the right time?
This communication and relay system between the brain and organs is the primary role of the vagus nerve. The vagus nerve plays a key role in the function of the autonomic nervous system.
What does the vagus nerve do?
1. Controls vital functions
It regulates heart rate, blood pressure, breathing, digestion, and more.
2. Promotes relaxation
It helps the body return to a calm “rest and digest” state after stressful events.
3. Links the brain to the gut
The vagus nerve plays a role in the gut-brain connection, affecting digestion and gut health.
4. Helps with mood and mental states
It influences anxiety, stress, mood disturbances such as depression, motivation, and resilience.
How does the vagus nerve work?
After the vagus nerve leaves the brain and starts its journey down the brainstem, it exits the cranium from behind the ear and travels down the side of the neck. It runs very close to either side of the throat, or anterior neck region. We have both a left and a right vagus nerve, which continue under the collarbone alongside blood vessels. As it travels downward, it branches off to various organs, starting with the thyroid and continuing down to send branches into the lungs, heart, and thymus. Eventually, it distributes many branches to the organs of the abdominal cavity, including the liver, kidneys, gallbladder, stomach, pancreas, spleen, and gastrointestinal (GI) tract.
The communication highway
Your vagus nerve is continuously working, communicating, and controlling the interrelationship between all the organs and the musculoskeletal system while simultaneously reporting back to the brain.
When you drink a cup of coffee, your vagus nerve receives intel from the gut that caffeine is being absorbed through the stomach lining and into the bloodstream. This immediately signals the vagus nerve to communicate with the heart, lungs, stomach, and muscular system to respond. Too much caffeine can cause jitters or anxiety, tense muscles, and changes in mood. Multiple systems are affected.
The vagus nerve helps create homeostasis, which is the balance, communication, and interconnection of all our organs and systems working together as a collaborative team. If we are being chased, the vagus nerve is the chief officer signaling the adrenal glands to release adrenaline, the heart to beat faster, the lungs to breathe deeper, and the arteries to dilate. This sends oxygenated blood to the muscles, allowing them to contract and respond quickly. All of this happens in a split second, letting the brain process and react accordingly.
Research and homeostasis
There is an enormous amount of research being conducted today to better understand and work with the vagus nerve. Behavioral techniques have shown significant results in calming the response of the autonomic nervous system. Deep breathing techniques, yoga, therapy, and other methods have been shown to have a dramatic impact on assisting in the homeostasis of the vagus and autonomic systems. Understanding the anatomy and orientation of the vagus nerve, as well as where it travels throughout the body, helps in treating it.
We can now see how a whiplash injury to the neck can significantly affect vagus nerve function, whether by overstretching, compression, or other means, thereby interrupting homeostasis and disrupting communication with the organs.
Whole-body health
As clinicians working with patients who have multiple disorders, it is imperative to think outside the box, viewing the patient as a whole rather than compartmentalizing the body into separate systems. If an organ like the liver is affected, it will trigger a full-body response due to the function of the vagus nerve. This is why the statement “What happens in Vagus does not stay in Vagus” holds true, it impacts and spreads throughout the entire visceral system.
Understanding anatomy and the nervous system is the first step in realizing why Neural Manipulation has a tremendous impact on healing. Read 5 Incredible Health Improvements Through Nerve Manipulation Technique to learn more.
Working with a holistic health practitioner who treats the body as a whole and focuses on the root cause has been proven to provide long-lasting wellness results.
Read more from Dr. Keelin Regan-Reed
Dr. Keelin Regan-Reed PT, DPT, Orthopedic and Neural Manual Physical Therapist
Dr. Keelin Regan-Reed PT, DPT, is a licensed manual Doctor of Physical Therapy specializing in Neural Manipulation. She is able to "listen" to the cranial rhythm in the brain and body by following the cerebral spinal fluid flow as it works around the brain and spinal cord to the peripheral nerves throughout the body. Just like a clinician can "feel" for the pulse in your wrist to listen to your blood flow and heartbeat, the fluid of the brain and nerves has a similar "feel" of pressure changes. Our bodies hug around lesions and restrictions, thus changing the rhythm of the fluid. Dr. Keelin can detect this change and follow where the lesion is and make the necessary corrections and/or releases so the body can then heal on its own.
