The Vagus Nerve


The vagus nerve is the 10th cranial nerve and is also referred to as the wandering nerve. 

It emerges from the brainstem and splits to travel down the left and right side of the neck into the body. It activates the throat muscles, regulates our heart rate, and ensures that the respiratory, digestive, and circulatory systems work properly. Most of its nerve fibers are sensory and they provide critical feedback to maintain homeostasis in the body.

The vagal nerves are the primary nerves connected to the parasympathetic nervous system, which is responsible for our “rest and digest” processes.

Vagus nerve vector illustration. Labeled anatomical structure scheme and location diagram of human body longest nerve. Infographic with isolated ganglion, branches and plexus. Inner biological ANS.

The following involuntary processes are controlled by the vagus nerve:

  • Digestion
  • Mood
  • Blood pressure, heart rate, and breathing
  • Saliva and mucous production
  • Taste
  • Speech

If the vagal nerves are damaged, digestive function can be impaired. Diabetes, abdominal surgery, and viral infections can cause damage to the vagal nerve.

Vasovagal fainting can also occur if the vagus nerve over-responds to stimuli such as heat, stress, pain, anxiety, or hunger.

Signs or symptoms that the vagus nerve is not functioning as it should include:

  • Bloating and abdominal pain
  • Problems swallowing
  • Heart rate fluctuations
  • Blood pressure or blood sugar fluctuations
  • Hoarseness, loss of voice
  • Dizziness or fainting
  • Reflux, nausea, or vomiting

Vagal tone exercises can be helpful to stimulate the vagus nerve. Increasing your vagal tone activates the parasympathetic nervous system, which enables our bodies to get back to a relaxed state more quickly after exposure to stress.

Vagal tone can be measured by tracking heart rate, breathing, and heart rate variability. The higher our heart rate variability the better our vagal tone will be.

Vagal tone exercises include:

Cold water immersion

Studies show that cold water immersion lowers the sympathetic “fight or flight” response and increases the parasympathetic “rest and digest” response.

Breathing exercises

Deep breathing is essential for proper vagal tone. Breathing in deeply from the diaphragm activates vagal tone and expanding the breath into the stomach with a long and slow exhale is key to stimulating the vagus nerve so that you can reach a state of relaxation.

Gargling, humming, singing

Since the vagus nerve is connected to your vocal cords and the muscles at the back of your throat, singing, humming, and gargling can activate these muscles and stimulate your vagus nerve. This has been shown to increase heart-rate variability and vagal tone.

Listen to my interview with Brad Kirsten from Radio Cape Pulpit on 15 December 2022 to learn more. Listen to my next interview on Thursday at 7.45am