Let me introduce you to one of the best (and most important) nerves in your body...
The Vagus Nerve
What is the Vagus Nerve?
The vagus nerve, also known as the tenth cranial nerve or cranial nerve X, is the longest nerve of the autonomic nervous system which controls involuntary body functions. The vagus nerve is tasked with regulating critical body functions such as heart rate, blood pressure, breathing, and digestion.
When in a good state the Vagus Nerve can do the following -
• Turn on neurogenesis, helping our brains sprout new brain cells. • Rapidly turns off the stress, hyper-arousal, and fight/flight via the relaxation response. • Sharpen our memories. • Fight inflammatory disease. • Help you resist high blood pressure. • Block the hormone cortisol and other oxidizing agents that age and deteriorate the brain and body • Block systemic (body-wide) inflammation - a major factor behind aging and poor health. • Help to overcome depression and anxiety. • Help you to sleep better. • Raise levels of human growth hormone. • Help overcome insulin resistance. • Turn down allergic responses. • Lower the probability of getting stress and tension headaches. • Help spare and grow our mitochondria- this is a key to maintaining optimal energy levels and not harming our DNA and RNA. • Affect our overall ability to live longer, healthier, and more energetic lives.
So an extremely important nerve then.
Symptoms of poor Vagus Nerve Tone
1. Cervical (the neck region)
Difficulty Swallowing
Swallowing is one of those reflex actions that we usually take for granted, but it requires a complex coordination of several different muscles around your throat.
As you swallow a number of reflex actions occur which shut the nasal cavities and open the oral cavities, followed by movements of the tongue and esophageal contractions which push down into the stomach. The vagus nerve plays an important motor and sensory role in this process, working in concert with a number of other cranial nerves.
Disfunction in the vagus nerve can therefore make swallowing difficult and even dangerous.
Changes in your voice
The motor division of the vagus nerve is responsible for the control of your vocal chords. If your voice changes inexplicably, especially if it becomes hoarse or strained, this can be a sign of vagus nerve damage. You may also experience difficulty talking or coordinating the movement of your tongue when you speak. It may or may not be accompanied by a general feeling of discomfort around the region of the throat.
Dry Mount and/or Persistent Cough
The vagus nerve is one of three cranial nerves which communicate taste signals back to the brain. Studies have shown that stimulation of the signals in the vagus nerve induce salivation, which is necessary to keep our mouth moist and to protect our oesophagus from stomach acids.
If signals are not carried correctly by the vagus nerve this can result in an unusually persistent dry mouth and throat. And because the vagus nerve also helps control coughing, this can also translate into a persistent cough.
2. Cardiovascular (HRV)
The rate at which your heart beats actually varies from beat to beat as the heart makes small adjustments depending on the body’s demands. The measure of how responsive the heart is to changing needs from the body is referred to as heart rate variability (HRV).
HRV is considered more important than straight forward resting heart rate in predicting or assessing your general health and fitness.
HRV is also one of the best measures we have for the health of the vagus nerve (often referred to as vagal tone). Because HRV and vagal tone are so closely linked, HRV is one of the best early warning signs that there may be problems. Because the two are so closely linked, a poor vagal tone can also reduce your HRV because a poorly performing vagus nerve is less able to carry the messages to and from your brain that allow careful regulation of each heart beat.
In more severe cases, your heart may beat too slowly (bradycardia) or may experience severe disruptions in its beating (arrhythmia) and may be associated with chest pain.
Blood Pressure
The vagus nerve also controls what is called the baroreflex, which is a rapid vascular response which helps the body maintain a near constant blood flow during other environmental and bodily changes. So if your heart rapidly increases, the baroreflex will dilate your blood vessels to reduce immediate blood pressure.
Dizziness or fainting
Vagus Nerve related cardiovascular problems may result in low blood pressure, which can lead to feelings of dizziness; in extreme situations, if it allows your blood pressure to drop too far, it can result in fainting. If any of this happens frequently, it may indicate that there is something wrong with your vagus nerve.
3. Abdominal
The vagus nerve is the main nerve that connects your brain and your guts. The brain-gut connection is now understood by science to be crucial to many aspects of our health. If you are experiencing any problems with your digestion, this could be a result of low vagal tone. your doctor.
4. Inflammatory
The inflammatory response is part of the body’s defense system. When you become injured or unwell, all or part of your body becomes inflamed as your body attempts to heal. However, the degree of inflammation must be carefully regulated by the body; otherwise, over-inflammation can become a problem.
A low vagal tone can result in nervous system balances which lead to such over-inflammation. Chronic low-grade inflammation is now believed by scientists to be associated with almost all age-related illnesses. And this is further linked to a declining vagal tone as we age. While this is strongly linked to age, it can begin to occur at any time in your life and may be triggered by stress or injury.
This can manifest itself in autoimmune conditions such as rheumatoid arthritis, the buildup of fluids in the parts of your body, particularly in the joints, causing redness, pain or loss of mobility or function. In mild cases, you might experience fatigue or headaches; but in more serious chronic cases, you could develop conditions such as depression or irritable bowel syndrome (IBS).
Recently, studies have associated chronic illnesses such as post-viral fatigue, (which now has been renamed as long-Covid) with residual inflammation in the body resulting from initial infection.
5. Mood
Mood is often greatly affected by the state of our body. Levels of hunger, fatigue, quality of sleep and mild chronic pain or inflammation can all reduce your mood levels. The majority of messages that are carried by the vagus nerve are sensory information about the state of bodily organs, which is all relayed back to the brain. Sensory information from internal, visceral organs is often vague and imprecise, so it is not always apparent to us that something is wrong.
If the vagus nerve is somehow damaged, it will have a negative effect on essential bodily functioning, exacerbated by low quality sensory feedback to the brain. Rather than being experienced directly as pain, this often translates into a shorter temper, feelings of anxiety or severe depression. If you notice such changes happening slowly, it could be a sign that something isn’t quite right with your Vagus Nerve, or with your autonomic nervous system in general.
6. Cognitive Functions
This symptom of low vagal tone is the one that people find the most surprising. But as the vagal nerve enters the brain, it merges with a part of the brain stem, which is in turn linked to many cognitive networks in the brain. The exact flow of information through these networks is not fully understood by scientists, but by following activation levels in these networks, it is possible for scientists to gain some idea of the brain’s interconnected pathways.
Low vagal tone has, in such a way, been linked to memory, learning and concentration. It is not clear if a decline in vagal tone directly causes this kind of cognitive decline in old age, but there does seem to be some link between the two. Difficulty concentrating, poor memory or difficulties in learning have also been linked to low vagal tone in younger people, though this is less common.
Testing Ventral Vagal Function
You may need a partner for this. This is a really powerful technique that can have a profound impact on how you address your body. Remembering where all the powerful neural innervations are, one of the innervations of the ventral Vagus Nerve is the throat.
Grab a partner and a flashlight.
Have your partner look at the inside of the mouth at the back of the throat at the uvula that drops down right in the center.
Now, perform an “ah, ah, ah” sound.
When you open your mouth, you can use a tongue depressor or your fingers to push down your tongue so the uvula and soft palate can be more visible.
Your partner needs to look at the uvula to see if there is a deviation to one side.
What you’re looking for, specifically, is if there’s any deviation from one side to the other. If the uvula pulls over to one side, then that is indicative of ventral vagal nerve dysfunction. If it moves up symmetrically, then that means that you are in a state of social engagement. So, if you have the soft palate moving up on one side, let’s say it’s moving up on the left side, and not moving up on the right side, then that would be indicative of a dysfunction of the pharyngeal branch of the ventral Vagal Nerve.
Now, that you’ve tested let’s move into how to stimulate the vagus nerve.
Vagus Nerve stimulation: The basic exercise
If your test indicated that you had a ventral vagal nerve dysfunction, perform the basic exercise for vagus nerve stimulation.
Lie on your back on the ground.
Interlace your fingers and bring them behind your head- right at the base of the skull
Look with your eyes to the right until you sigh, swallow, or yawn, and then repeat on the other side.
You may blink during the exercise.
Now that you’ve stimulated it, retest your vagal nerve and see if there was a change.
This is just one way to measure your autonomic nervous system function. This is also just one way out of many to stimulate your vagus nerve. However, recognize there are so many ways to become more aware, more in tune, and map your nervous system. You are completely in control of what’s happening in your life.
How you can activate the Vagus Nerve more
Vagus nerve stimulation can be turned on easily though a number of breathing and relaxation techniques: •Deep/slow belly breathing. •'OM' Chanting •Cold water face immersion after exercise •Filling the mouth with saliva and submerging your tongue to trigger a hyper-relaxing vagal response. •Loud gargling with water •Loud singing
To practice deep breathing, inhale through your nose and exhale through your mouth. Remember to: •Breathe more slowly. •Breathe more deeply, from the belly. •Exhale longer than you inhale.
Using Breathing to Reduce Pain You can learn to use breathing exercises to shift your focus away from pain.
The human mind processes one thing at a time. If you focus on the rhythm of your breathing, you're not focused on the pain. The moment we anticipate pain, most of us tend to stop breathing and hold our breath. Breath holding activates the fight/flight/freeze response, it tends to increase the sensation of pain, stiffness, anxiety, or fear.
You can proceed as follows: take a deep inhalation into your belly (i.e. expanding your diaphragm) to the count of five, pause, and then exhale slowly through a small hole in your mouth.
While at rest most people take about 10 to 14 breaths per minute.
To get into parasympathetic/ relaxation/healing mode it is ideal to reduce your breath to 5 to 7 times per minute.
Exhaling through yourmouth instead of nose makes your breathing more of a conscious process, and helps you to observe your breath more easily. As you reduce your breaths per minute and get into parasympathetic mode, your muscles will relax, dropping your worries and anxieties. The oxygen supply to your body's cells increases and this helps produce endorphins, the body's feel-good hormones.
Tibetan monks have been practicing 'conscious breathing' for decades, but there is nothing mysterious about it. You can enhance your experience by imagining that you inhale IN love, and exhale OUT appreciation.
These ancient techniques also will improve memory, fight depression, lower blood pressure, or heart rate, and boost your immune systems — and it's free!
An interesting study was performed by the International Journal of Yoga in 2011, where 'OM' chanting was compared with pronunciation of 'SSS' as well as a rest state to determine if chanting is more stimulatory to the vagus nerve. The study found that the chanting actually was more effective than either the 'sss' pronunciation or the rest state. Effective 'OM' chanting is associated with the experience of a vibration sensation around the ears and throughout the body. It is expected that such a sensation is also transmitted through the auricular branch of the vagus nerve and will produce limbic (HPA axis) deactivation.
How to chant? - Hold the vowel (o) part of the 'OM' for 5 seconds then continue into the consonant (m) part for the next 10 seconds. Continue chanting for 10 minutes. Conclude with some deep breathing and end with appreciating yourself.
Cold Water Physical exercise causes an increase in sympathetic activity (HPA axis - fight/flight, stress response), along with parasympathetic withdrawal (resting, digesting, healing, immune system), resulting in higher heart rates (HR). Studies have found that cold water face immersion appears to be a simple and efficient means of immediately accelerating post-exercise parasympathetic reactivation via the vagus nerve, stimulating the reduction of heart rate, motility of the intestines, and turns on the immune system.
It is also effective in a non-exercise environment to activate the vagus nerve. In cold-water face immersion, try to be seated and bend yourr head forward into a basin of cold water. The face is immersed so that the forehead, eyes, and at least two-thirds of both cheeks were submerged. Water temperature needs to be kept at 10-12°C.
Increased Salivation also increased Vagus Nerve stimulation. The calmer the mind and the deeper the relaxation, the easier the stimulation of salivation is. When the mouth is able to produce copious amounts of saliva, you know that the Vagus Nerve has been stimulated and your body is in the parasympathetic mode. To stimulate salivation, try relaxing and reclining in a chair and imagine a juicy pear. As your mouth fills with saliva, just rest your tongue in this bath (if this doesn't happen, just fill your mouth with a small amount of warm water and rest your tongue in this bath. Just the practice of relaxing will stimulate the secretion of saliva). Now relax further, and feel your hands, feet, hips, back of the neck and head all relaxing. Breathe deeply into this feeling and stay here as long as you can.
Having a healthy Vagus Nerve is literally life saving so I encourage you to encorporate some of these exercises into your daily or weekly routine to sharpen up your vagal activity.
Disclaimer - I have a parasympathetic dominant nervous system so have a vested interest in all things Vagal!
Now, there are a very large number of bodily movements, having their source in our nervous system, that do not possess the character of conscious actions.