Activating the Vagus Nerve

The vagus nerve is one of the longest and most important nerves in the body. 

As the primary nerve of the parasympathetic nervous system, it keeps the  sympathetic or “fight or flight” nervous system in check and mediates many health benefits. While it operates even without us having to think about, it can be activated by us intentionally. 

The vagus nerve has it nucleus in the lower part of our brain called the brainstem, which is sometimes called the “reptilian brain.” It courses through our neck and chest into our abdomen, sending branches to our face, heart, lungs, digestive system, and other organs. 

The sympathetic nervous system causes our heart rate, blood pressure, and blood sugar to rise. 

While these may adaptive as part of the “acute stress response,” helping us flee from or stay and fight a predator or enemy, they are unhealthy when they persist. 

Chronic stress causes long-term elevations in these parameters, predisposing us to hypertension, cardiovascular diesease, type 2 diabetes, and even dementia. 

How can we bring these changes back down to normal when the nedd to run or fight is no longer present? Or when there is no actual threat and our sympathetic nervous systemis activated simply by our thoughts? We can learn to activate the vagus nerve and the parasympathetic nervous system.

The simplest way to activae the vagus nerve is by slow, deep breathing. We inhale through the nose to a slow count of 3, pause for a count of 3, and exhale through our nose or mouth to a count of 4. Doing this for even a few minutes can lower our heart rate, blood pressure, and blood sugar.

Another way to activate the vagus nerve is with ice. We can hold an ice pack over our face for a few minutes or get in a cold shower or bath. While the latter may temporarily activate the sympathetic nervous system, this abates after a minute or so and the “diving” or vagal reflex kicks in and the parasympathetic nervous system predominates via the vagus nerve.

We can also use gentle pressure with our hand, a softball, or a grapefruit over the pulsatile carotid artery in our neck to fire the vagus nerve. The “carotid body” receptors sense the pressure and activate the vagus nerve.

There is a growing number of devices on the market to increase vagal activity, and the parasympathetic nervous system, but these simple methods require no pricey equipment and are always acessible. 

Let’s activate the vagus nerve when we are stressed and become healthier and happier!

Note: Although I am a physician, the content in this article is not meant to diagnose, treat, cure or prevent illness or disease in the reader – it is for educational purposes only.

References

• Katona, P. G., Poitras, J. W., Barnett, G. O. & Terry, B. S. Cardiac vagal efferent activity and heart period in the carotid sinus reflex. Am. J. Physiol.1970;28(4):1030-42.
• Good CB. Use of ice-water bag to obtain dive reflex. Am J Med. 1992 Jul;93(1):116
• Laine Green A, Weaver DF. Vagal stimulation by manual carotid sinus massage to acutely suppress seizures. J Clin Neurosci. 2014 Jan;21(1):179-80.