Making Sense of Medicine: The wanderer in your brain

Anxiety attack? Sleepy after a big meal? Heart racing or creeping? GERD? One thing that all these conditions have in common is their relationship to your vagus nerve.

I often include reference to the vagus nerve in my columns. It’s easy and natural to do this because vagus affects so many of your organs and is implicated in several undesirable, and desirable, conditions you may experience.

This column is specifically about vagus, its origin, function, travels and more. I write this because when we talk about fitness or conditioning or living a healthy lifestyle, vagus generally gets a lot less attention than it deserves.

A truly healthy person lives in such a way as to ensure that vagus can do its work when it’s needed.

What is vagus?

The vagus nerve is the 10th of 12 so-called cranial nerves, or actually pairs of nerves that are usually referenced as a single nerve. A cranial nerve is one that begins in your head as opposed to those nerves that begin in your spinal cord.

Vagus is a word taken directly from Latin, where it meant wandering or a wanderer. It carried a lot of other meanings, as well, like a fugitive or rambling or stray and more.

In our case, wandering is perhaps the best interpretation, as the left and right branches of vagus wander over a lot of your body. It’s in your brain, your eyes, your mouth, your neck, your lungs, your heart, much of your gut and places in between. In women, it affects even the reproductive organs.

In recent years, there has been considerable research showing how gut problems can affect mental health, and vagus is a prime link between gut and brain.

The primary function of vagus is to slow things down. For this reason, the effects of vagus are referred to as your rest-and-digest response. It’s the antithesis of your all-too-familiar fight-or-flight response.

To be sure, vagus is not the only nerve to affect these areas, but it certainly is primary.

What can go wrong?

When working normally, vagus helps ensure that your heart beats at what we have come to call a normal rate, somewhere between about 60 and 100 beats per minute. Under stress, it’s natural for your heart rate to increase, but then slow down when the stress is relieved.

If vagus is not doing its job, then your heart rate can increase to more than 100 beats per minute even when you are at rest. This is called tachycardia, the Latinized form of the Greek meaning swift heart.

Although underperforming is often a problem with vagus, the converse is true, as well. In some cases, vagus gets overstimulated. Among other things, this can result in a heartbeat that’s too slow, bradycardia; the brady- prefix means slow.

Similarly for other organs, vagus can be over- or under-stimulated. Vagus helps control the release of stomach acid, for example, and so chronically low stomach acid may be a result of too little vagus stimulation. This can lead to conditions like irritable bowel syndrome and may affect your ability to absorb vitamin B-12.

A few lists

It’s hard to be complete about vagus without just giving lists of things, so here are a few incomplete lists related to vagus.

Things that vagus stimulation does: increases thyroid function, lowers heart rate, increases movement of food through your gut (peristalsis), reduces sweating, increases the feeling of being full from food, decreases inflammation, increases the creation of new neurons.

If you have the following symptoms, it’s possible that your vagus is not functioning properly: weight gain, IBS, depression, anxiety, abnormal heart rate, fainting, chronic fatigue, swallowing problems, delayed emptying after eating, GERD, B-12 deficiency, chronic inflammation.

And here is yet another laundry list of conditions that stimulating vagus may help: anxiety disorders, depression, obsessive-compulsive disorder, heart disease, Alzheimer’s, migraines, fibromyalgia, obesity, tinnitus, alcohol addiction, autism, bulimia, multiple sclerosis, memory disorders, mood disorders, leaky gut.

What can you do?

There are some things you can do on your own to keep vagus functioning normally. Most of these have been at least partially validated through research.

Your body’s adjusting to exposure to cold has been shown to reduce the fight-or-flight response, and to stimulate rest-and-digest. This can be as little as splashing cold water on your face or drinking a glass of very cold water. Some people, braver than I, actually take cold showers for this purpose.

Singing or chanting is also effective at stimulating vagus. This can be humming, singing hymns, chanting “Om” while in your shower or energetic singing. Exercising the muscles in your throat is a good stimulator, and singing at the top of your lungs can have this effect.

Meditation is another outstanding way to keep vagus happy. Fight-or-flight and rest-and-digest are part of your autonomic nervous system. This means that they are beyond your conscious control, or at least that’s what was believed for a long time.

Fight-or-flight may be triggered by some external stimulus, but it can be triggered internally, as well, by stressful thoughts and your own actions. In the same way, rest-and-digest can be triggered by consciously observing whatever is happening in your mind without becoming attached to it.

Here is one common example of what to do. As you meditate, if you see a boat passing by, observe that there’s a boat passing by, but don’t get into it nor follow it.

There are many other ways to stimulate vagus: slow deep breathing, being in pleasant social relationships, prayer, gentle exercise, tai chi and laughing. By laughing, I don’t mean a kind of “tee-hee” laugh, but rather a whole body outrageous “ha-ha” laugh.

I also have myokinesthetic, or MYK, treatments that will either stimulate or quiet the vagus nerve.

At last

Caring for your vagus nerve is as crucial to your health as any exercise or diet or other regime. I urge you to take some time every day to stop whatever you’re doing, and make a space for vagus.


Bob Keller maintains a holistic pain management practice in Newburyport. His book, “Making Sense of Medicine: Medical Matters Made Simple,” is available locally or online. He can be reached at 978-465-5111 or