Articles

Evidence based

Evidence Based

This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of licensed nutritionists and dietitians strive to be objective, unbiased, honest and to present both sides of the argument.

This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

Vagus Nerve Damage Symptoms, and How to Deal with Them

Written by Dr. Michael Ruscio, DC on June 9, 2023

Written by Dr. Michael Ruscio, DC on June 9, 2023 — Reviewed by Dr. Hannah Hamlin

If Your Health Issues are Related to Poor Vagal Tone, Here’s a Plan to Improve Things

• Recognizing Vagus Nerve Damage Symptoms|
• Gut Health and the Vagus Nerve|
• The Vagus Nerve Helps Calm You|
• Vagus Nerve Stimulation|
• Other Potential Vagus Nerve Therapies|
• Start With the Basics|
• Vagus Nerve Health Can Be Simple|

If you’re interested in functional health and well-being you might have heard quite a lot about the vagus nerve lately. 

Recent research has shown this meandering nerve connecting the brain and internal organs is important in regulating many aspects of our physical and emotional health.

Symptoms associated with suboptimal functioning of the vagus nerve can be 1 2 3 4

• Mental (e.g., anxiety, and depression),
• Physical (e.g., inflammatory bowel disease, irritable bowel syndrome, abdominal pain, migraines)

But while having healthy vagus nerve activity (aka good vagal “tone”) is definitely important, not all the buzz around this nerve is on target.

In fact, many of the symptoms of vagus nerve dysfunction mimic the symptoms of a suboptimal diet and lifestyle, so it’s easy to confuse the two. 

In this article, we’ll take a deep dive into vagus nerve damage symptoms, and the specific therapies designed to heal the vagus nerve. But you may be able to improve suboptimal vagus nerve function, and feel better, simply by improving your underlying health, particularly your gut health.

Recognizing Vagus Nerve Damage Symptoms

The vagus nerve (in fact, there are two — one on the left side and one on the right) is the longest cranial nerve. It runs from the brainstem and travels to all the important organs of the body, including the gut, brain, and heart.

Symptoms related to impaired function of the vagus nerve can be fairly non-specific, or more well-defined.

Medically Diagnosed Vagus Nerve Damage

Some symptoms that are connected to more serious vagus nerve damage include 5: 

• Gastroparesis (the passage of food from the stomach to the intestines slows down or stops) 6
• Vasovagal syncope (physical or emotional stress causes an extreme reaction that means blood pressure drops too rapidly and you feel dizzy or actually faint)
• Difficulty swallowing, including loss of gag reflex 
• Hoarseness, wheezing, or loss of voice

If you have been medically diagnosed with the above symptoms of damage to the vagus nerve, and have the types of symptoms listed above, there will usually be an obvious underlying reason, such as diabetes, an autoimmune condition, or surgery that has caused physical trauma to the nerve.

Low Vagal Tone 

Where it gets a little less black and white is with a host of symptoms that could be related to less than optimal vagus nerve function, but might also have other causes.

For example, low vagal tone (poor sensitivity of the vagus nerve) has been associated with: 

• Gut conditions, including inflammatory bowel disease and irritable bowel syndrome 2
• Neurological conditions such as epilepsy and Parkinson’s disease 7 8
• Headache disorders, including migraine and cluster headaches 3
• Difficulties in regulating emotion 9
• Depression, anxiety, and PTSD 4

In these cases, it’s not known to what extent vagus nerve issues play a part. It’s also not clear if the conditions are caused by having inadequate/low vagal tone or vice versa.

If you’ve already taken care to eat healthily, destress and be active, but are still experiencing symptoms such as the ones above, the odds are higher that vagal tone could be the issue, and that specific vagus nerve therapies could help.

If you noticed symptoms after prolonged stress, trauma, or an infection, this could also be an indicator that your vagus nerve is to blame. Some infections, including COVID-19, have been suggested to cause damage to the vagus nerve 10.

Aiming to improve the health of your vagus nerve is always a good goal, regardless.

Gut Health and the Vagus Nerve

If you’ve heard of the gut-brain connection or the gut-brain axis, the vagus nerve is one of the most important components of this connection.

The vagus nerve collects signals and information from the gut (including chemical messaging put out by your gut microbiome) and sends it to the brain. 

80–90% of the fibers that make up the vagus nerve send information from the body back up to the brain. Information about things such as inflammation, appetite, bloating, and energy metabolism are communicated from the gut through to the brain in this way.

However, if you’ve ever experienced anxiety diarrhea when you’re feeling nervous you’ll also know that messages travel the other way around (from brain to gut) too 11 12.

The bottom line is that what is going on in our gut, including gut microbial imbalances (dysbiosis), and inflammation, can have a big bearing on your mental health and mood, and vice versa. 

The Vagus Nerve Helps Calm You

To understand some of the context around vagus nerve damage symptoms, an important thing to know is that this nerve is the main nerve of the parasympathetic nervous system. 

The parasympathetic nervous system is the branch of the autonomic nervous system that’s about “rest and digest”. It helps run life-essential processes, like digesting food, when we are calm and non-anxious.

Prolonged stress, or other trauma, can mean the opposite branch of your autonomic nervous system  — the sympathetic nervous system — stays hypervigilant (i.e. in chronic “fight or flight” readiness) even when there is no perceivable threat. 

Therapies that aim to improve the activity of the vagus nerve, are therefore aiming to relax and destress you.

HRV Measures Vagus Nerve Activity

Vagus nerve activity, or vagal tone, can’t be measured directly so the next best thing we have is to measure it indirectly, via heart rate variability, or HRV.

HRV measures how much variance there is between each individual heartbeat, and is a good proxy for your vagus nerve activity as this variance also reflects how active or inactive the parasympathetic versus sympathetic nervous system is at any one time.

Very broadly speaking, a higher HRV means more parasympathetic activity (and vagus nerve action) and has been linked with longevity 13, while low HRVs reflect more sympathetic action and are linked with health conditions like depression and anxiety 14

Many health tech wearables now measure HRV as you sleep and can be useful to track changes in your HRV/vagal tone. 

However, your HRV is highly individual and can’t be compared with another person’s. Instead, you should look for trends in HRV and not get too hung up on day-to-day ups and downs.

Vagus Nerve Stimulation

Vagus nerve stimulation (VNS) isn’t just a vague concept; it’s actually an FDA-approved treatment used in conventional medicine to treat epilepsy, obesity, and treatment-resistant depression 15 16.

However, in this case, we are talking about a surgically implanted device that works by periodically shocking the nerve into action. For the vast majority of people who may have more minor vagus nerve damage symptoms, this is too invasive and extreme.

If you want to try to stimulate the vagus nerve in a safer, milder way, something called transcutaneous auricular vagus nerve stimulation has many of the same benefits as a VNS implant, without the potential side effects of an implant. 

Transcutaneous auricular VNS involves using an external electrical stimulation device (such as a TENS unit) attached to the left ear, which has many vagus nerve endings. An alternative is cervical transcutaneous vagus nerve stimulation, which is used on the neck instead.

Studies looking at the effectiveness of non-invasive VNS in balancing the fight or flight (sympathetic) and rest and digest (parasympathetic) branches of the nervous system are conflicting 17.

However, there are a number of randomized clinical trials and some meta-analyses of trials that suggest that non-invasive vagus nerve stimulation can successfully 17 18 19:

• Slow heart rate (in about half of studies)
• Reduce circulating levels of inflammatory markers
• Significantly improve gastrointestinal pain, migraines, and pelvic pain 
• Improve dyspepsia (indigestion) symptoms
• Significantly improve depression and anxiety

These are impressive potential benefits for a therapy that has few downsides. However, transcutaneous vagus nerve stimulation has yet to be not widely used or promoted. You can find units for sale online, but I would first advise finding a healthcare provider who is educated in the use of transcutaneous VNS, and discussing it with them.

Other Potential Vagus Nerve Therapies

There are many other techniques purported to help activate the vagus nerve and/or parasympathetic activity. While they don’t have as much research backing as vagal nerve stimulation, some may be helpful, so you might want to give them a try.

However, no amount of experimenting with vagus nerve activation is likely to have a satisfactory effect on vagus nerve damage symptoms if you haven’t underpinned these techniques with healthy diet and lifestyle steps.

Also, if you find yourself obsessing a lot over vagus nerve therapies, it’s worth taking a step back. It’s all too easy to amp up our stress levels even more by feeling that we constantly need to address them!

With these caveats in mind, here are some other vagus nerve therapies you could try.

Emotional Freedom Technique (EFT)

The emotional freedom technique (EFT), sometimes referred to as “tapping,” is a mind-body practice that typically involves thinking of a distressing memory and pairing it with a self-acceptance statement while tapping 5 to 10 times with the fingers on acupressure points located on the head, hand, and torso 20

Tapping doesn’t directly target the vagus nerve, but appears to have benefits similar to those you get by activating your parasympathetic system.

A systematic review and meta-analysis that assessed the effect of EFT, found that it was associated with a significant improvement in anxiety scores.

Massage

Massaging the muscles in the neck/shoulder area (between the trapezius and sternocleidomastoid muscles below the base of the skull) is thought to stimulate the vagus nerve due to its close proximity, and to increase parasympathetic activity and vagal tone.

However, it’s likely you don’t need to be as precise as all that: in a study that compared specific vagus nerve massage with a more general soft shoulder massage, both increased vagal tone (measured indirectly by changes in HRV) to a similar degree. In fact, simply sitting and resting also yield improvements in HRV, but not to such an extent 21.

Deep Breathing Exercises

Taking deep, slow breaths may help to increase vagus nerve activity. In one study, people with slightly raised blood pressure had better vagal tone/HRV when they practiced slow breathing exercises (6 breaths per minute) twice a day for 5 weeks 22

A good rule of thumb to activate the parasympathetic nervous system is to make your exhalations longer than your inhalations when you practice breathing exercises. 

Singing, Humming, and Chanting

Singing, humming, and mantra chanting all increased vagal tone and HRV in one study 23. This effect is likely related to changes in breathing patterns that help stimulate the vagus nerve. Music therapy (whether listening to music or performing) also has the added bonus of increasing the hormone oxytocin, which can increase feelings of wellness. 

Meditation

Mindfulness meditation is another potential therapy for activating the vagus nerve. In a small 2015 randomized controlled trial, 60 people were subjected to induced stress and then had their HRV tracked during either a 10-minute mindfulness meditation session or a 10-minute rest period. 

The results showed that meditation significantly increased some people’s HRV and vagal tone during meditation. However, people who were perfectionists didn’t seem to receive the same benefits to vagal tone as people who were not 24.

Start With the Basics to Support Your Vagus Nerve Health

Rather than going down a rabbit hole of unsupported practices, you can make more basic changes that soothe gut, mental health, and physical symptoms in a broader and more long-lasting way. 

Many of the vagus nerve damage symptoms, such as digestive system and mood issues, are similar to those that are caused by inflammation, microbiome imbalances, and poor diet.

Eat an Anti-inflammatory Diet

There is a limited amount of research examining the influence of diet on the vagus nerve. But of the evidence that does exist, it appears that dietary factors that are good for general health are also good for vagal tone. 

• For example, one research review examining the role of nutrition on HRV/vagal tone found that eating a healthy Mediterranean diet was associated with better vagal tone (as also were consuming pistachios, oily fish, and polyphenol-rich red wine, which are both likely to feature in a Mediterranean diet) 25.
• A separate study showed fish oil supplementation modestly but significantly increased HRV/vagal tone 26. 

A Mediterranean-style diet with plenty of oily fish is also an anti-inflammatory diet, so it is not a surprise that his way of eating can improve both gut health and vagus nerve health (both of which can be negatively affected by inflammation).

Take Probiotics

Another way you may be able to optimize gut health and home gut/brain communication via the vagus nerve is with probiotics.

Probiotics can help to treat the dysbiosis that alters brain function 27.

In my practice, I’ve found patients who supplement several strains of bacteria at once have the best gut and mental health results.

Exercise Regularly

Aerobic exercise, resistance exercise (weights), yoga, and stretching have been found to improve the health of the vagus nerve 28

In one study, regular sessions of high-intensity exercise improved vagal tone and resulted in better heart function in patients with chronic heart failure 29. 

The specifics of what type of exercise is best for dealing with vagus nerve damage symptoms isn’t very clear. However, being sedentary is definitely the enemy of good vagal tone, so the important thing is not so much what type of exercise you do, but just to be regularly active.

Vagus Nerve Health Can Be Simple

In our deep dive into vagus nerve damage symptoms, we’ve learned that there are several ways to potentially improve your vagus nerve and parasympathetic function.

Some techniques to improve vagal tone have better evidence behind them than others, but most can be potentially useful. However, tackling the basics of good health, including a gut-healthy diet, and regular exercise is a first priority.

For more individualized guidance, you may want to reach out to our clinical team here at the Ruscio Institute for Functional Health. 

The Ruscio Institute has developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.