The Vagus Nerve: What you need to know

by | Apr 26, 2022

I t always comes down to anxiety, depression, and stress, doesn’t it? “Sure, the meds and therapy help, but isn’t there something creative I can add to the mix?” Let’s talk about the vagus nerve…

When the vasovagal response is triggered, a sudden drop in heart rate and blood pressure occur. When that happens, blood vessels in the legs may widen…

If we rely solely upon meds and therapy for mood and anxiety disorder relief, we’re doing ourselves a disservice.

There are all sorts of creative intervention targets and techniques we can add to our treatment regimen. We’re going to discuss one of them – the vagus nerve.

Because there’s so much valuable information to share, we’ll do this in two parts. In this piece we’ll get to know the vagus nerve and we’ll get into how to deal with some of the problems it can present, and manage, in part two.

What is the vagus nerve?

Before we get rolling, why should we even bother with learning about the vagus nerve?

Absorb these excerpts from “Vagus Nerve as Modulator of the Brain-Gut Axis in Psychiatric and Inflammatory Disorders.” The article, written by S. Breit, A. Kupferberg, G. Rogler, and G. Hasler, appears on Frontiers in Psychiatry…

  • …discuss various functions of the vagus nerve which make it an attractive target in treating psychiatric and gastrointestinal disorders
  • …preliminary evidence that vagus nerve stimulation is a promising add-on treatment for treatment-refractory depression, posttraumatic stress disorder
  • …stimulation of vagal afferent fibers in the gut influences monoaminergic brain systems in the brainstem that play crucial roles in major psychiatric conditions, such as mood and anxiety disorders (my note: monoaminergic refers to the monoamine neurotransmitters: dopamine, epinephrine, norepinephrine, serotonin)

Much more in their article, but can you see why learning about the vagus nerve is well worth the bother?

Cranial nerves

The vagus nerve is the tenth of our twelve cranial nerves. They’re noted by Roman numerals. What makes cranial nerves unique is their emergence in pairs – left and right side – directly from the brain, not from segments of the spinal cord.

Ten of the twelve cranial nerves, including the vagus, are components of the peripheral nervous system. In short, it’s the relay between the brain, spinal cord, and the rest of the body.

Vagus nerve

what does the vagus nerve do

The vagus nerve – right side

The vagus nerve, cranial nerve X, is in green in our featured image and you can see its path in the image above.

Vagus comes from the medieval Latin: “wandering.” And I’m sure the name was chosen because the cord-thick nerve originates in the brainstem, extends through the neck and chest, and terminates in the abdomen. Remember, there are two “vagal nerves.”

The vagus nerve is our primary parasympathetic nerve. Parasympathetic “rest and digest” action down-regulates our fight/flight response when a threat has passed. So it restores order in our mind and body.

The vagus nerve is also the connection between the central nervous system and the enteric nervous system (gastrointestinal). It’s known as the brain-gut axis.

Finally, the vagus nerve is a major player in inflammation management.

No wonder the vagus nerve supplies sensory and motor fibers to all of the major organs of the head, neck, chest, and abdomen.

What does the vagus nerve do?

In handling its assorted jobs, the vagus nerve controls or regulates involuntary functions such as…

Heart rate, blood pressure, sweating, muscle contractions and glandular secretions in the gastrointestinal system, immune system response, mood, mucus and saliva production, skin and muscle sensations, speech, taste, urine output, gag reflex

Are you beginning to see why the vagus nerve deserves our attention?

Vasovagal response and vasovagal syncope

The vasovagal response (aka vasovagal reflex) occurs when there’s excessive activation of the vagus nerve in the face of significant stress. “Vaso” referring to blood vessels, “vagal” to vagus. It’s a parasympathetic – “rest and digest” – overcompensation.

Here are some of the things we may experience…

Blurred or tunnel vision, cold and clammy skin, turning pale, feeling warm, sweating, dizziness, light-headedness, nausea, ringing in the ears, loss of bladder control, fainting

But what triggers the vasovagal response? These are the most commonly reported…

Emotional stress, a blood draw, the sight of blood, fear, gastrointestinal illness, a bowel movement, heat, physical pain, standing for a long time, standing up quickly, trauma

The biology

So we know what the vasovagal response looks like and its common triggers. But what’s the biology behind it all?

When the vasovagal response is triggered, a sudden drop in heart rate and blood pressure occur. When that happens, blood vessels in the legs may widen, which can cause blood pooling in the legs. And that can lead to a further drop in blood pressure.

What it all comes down to is compromised blood flow to the brain.

By the way, we all have different vasovagal response strengths. Some may faint at the mere mention of blood or a hint of coming trouble. Others may never experience the response.

Vasovagal syncope                     

So far we’ve talked about feeling faint during the vasovagal response. Well, fainting is a real possibility. It’s called vasovagal syncope – a fancy word for fainting. The loss of consciousness typically lasts a few minutes and in most cases it’s on with the show in short order.

Being prepared is important, isn’t it? Well, here are some things we can do if a vasovagal response episode is knocking on the syncope door…

Lie down for ten minutes or so, lower our head between our knees, drink some water, don’t stand up quickly, during bowel movements: try to stay relaxed, sit on the toilet with head down and legs crossed. Keeping a sufficient and steady blood pressure is the goal.

If you’re experiencing numerous or intense vasovagal response episodes, with or without fainting, be sure to chat with you doc.

See you in a bit

No doubt, meds and therapy can bring relief for symptoms of anxiety, depression, and stress. But why not add more to our treatment mix?

The vagus nerve is a great intervention target. And we’ll get into how to stimulate it in part two: The Vagus Nerve: What you need to know | Work it.

See you in a bit.

Vagus Nerve as Modulator of the Brain-Gut Axis in Psychiatric and Inflammatory Disorders is a long and scientifically detailed read. You may enjoy it.

info sources; Verywell Health Kenhub Cleveland Clinic Frontiers in Psychiatry

featured image credit Kenhub

Looking for more Chipur mood and anxiety disorder info and inspiration titles? All but a tap away.

Bill White is not a physician and provides this information for educational purposes only. Always contact your physician with questions and for advice and recommendations.

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