The vagus nerve has become the internet's favourite body part.
Authors
- Katie Edwards
Commissioning Editor, Health + Medicine and Host of Strange Health podcast, The Conversation
- Dan Baumgardt
Senior Lecturer, School of Psychology and Neuroscience, University of Bristol
On social media, it is everywhere. People hum into their phones, gargle with theatrical enthusiasm, dunk their faces into bowls of ice water and poke at their ears in the hope of "activating" it. Influencers describe it as a hidden master switch for calm, digestion and emotional balance. Some claim that learning to control it can transform everything from anxiety to inflammation.
All of which makes it sound faintly mystical. In reality, the vagus nerve is not a wellness trend . It is a real, physical nerve. And a surprisingly important one.
In the fourth episode of the Strange Health podcast, we turn our attention to the body's longest cranial nerve and ask a simple question: what does the vagus nerve actually do, and can we really hack it?
To find out, we spoke to Arshad Majid, a professor of cerebrovascular neurology at the University of Sheffield and an expert in vagus nerve stimulation. As he explains, the vagus nerve is one of 12 cranial nerves that emerge directly from the brain. Its name comes from the Latin for "wanderer", which is fitting. It begins in the brainstem and travels down through the neck into the chest and abdomen, connecting to the heart, lungs, gut and even the liver.
It is less a single-purpose wire and more a busy two-way information highway. Most of its activity involves carrying signals from the body back to the brain, keeping it updated on what is happening internally. It is also part of the autonomic nervous system, which regulates the processes we do not consciously control, such as heart rate, breathing and digestion.
Within that system, the vagus nerve plays a key role in the parasympathetic response, sometimes known as "rest and digest". When this system dominates, heart rate slows, blood pressure drops and the body shifts into a calmer, more restorative state. That much is well established. What is less clear is how easily we can influence it ourselves.
Despite the explosion of vagus nerve content online, Majid is cautious about claims that it can be switched on like a light. Slow breathing , singing, humming or splashing cold water on the face may indirectly influence vagus nerve activity, but it is not an on-off button and the effects vary widely between people. In some cases attempting to stimulate the vagus nerve can trigger headaches and even depression.
Vagus nerve stimulation is more firmly grounded in medicine. Implanted devices that stimulate the nerve directly have been used for years to treat conditions such as treatment-resistant epilepsy and depression. More recently, researchers have begun exploring non-invasive approaches. Some medical devices stimulate a small branch of the vagus nerve in the ear using gentle electrical pulses.
Majid and colleagues are currently running a major clinical trial investigating whether this kind of non-invasive stimulation can improve arm function in people recovering from stroke by encouraging the brain to rewire itself. If successful, it could transform rehabilitation for many patients.
Despite the online hype, then, scientists are only beginning to understand what this wandering nerve can do and how it might be used therapeutically.
Listen to Strange Health to find out why the vagus nerve has captured so much attention, what the science actually says, and why the next few years of research could reshape how we treat conditions from stroke to depression.
Just maybe hold off on aggressively poking your ear in the meantime.
Strange Health is hosted by Katie Edwards and Dan Baumgardt. The executive producer is Gemma Ware, with video and sound editing for this episode by Anouk Millet. Artwork by Alice Mason.
In this episode, Dan and Katie talk about social media clips via TikTok from drjoedamiani , ayuswellness and prettyspatricia .
Listen to Strange Health via any of the apps listed above, download it directly via our RSS feed or find out how else to listen here . A transcript is available via the Apple Podcasts or Spotify apps.
Katie Edwards is Commissioning Editor for Health and Medicine at The Conversation in the UK. Arshad Majid receives funding from the National Institute of Health research (NIHR) EME Programme for the TRICEPS trial which is investigating tVNS in stroke recovery.
Dan Baumgardt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
