The Vagus Nerve
by Katharina Zwielich, MSc
When we struggle with stress, anxiety, and uncomfortable emotional arousal, the part of our nervous system called the sympathetic nervous system is in overdrive. The autonomic nervous system is the part of our nervous system that we don’t control consciously – think breathing, digesting, and heartbeat. There are two subsystems that, when activated, direct these activities in different ways. The sympathetic nervous system arouses while the parasympathetic nervous system calms.
When we feel threatened, our sympathetic nervous system is activated and our behavioural response is fight, flight or freeze. Our body releases a stress hormone. We are then in a state of limited mental and bodily functioning in order to use all our energy to stay safe and respond to the perceived threat. This can mean increased heart rate, flat breathing, and digestive issues. We may also experience egocentric bias and limited ability to be present with people around us. This may be helpful when we are in actual danger – a car is about to hit us, a tiger is chasing us, and so on. However, in today’s world we often perceive threats when we are objectively safe. These threats can for example be social threats or anxiety linked to excessive worry. Typically the calming parasympathetic response kicks in automatically after a threatening situation. But if we find ourselves in a chronic state of activated sympathetic response there are ways to kickstart our parasympathetic nervous system to help us relax.
The vagus nerve plays an essential role in the parasympathetic nervous system. Its name stems from the Latin term for “wandering”. While called the vagus nerve (singular), it is actually two nerves, and the longest ones in our bodies, connecting the brain to various organs. Like its name suggests it wanders through the body. Information travels in two directions via the vagus nerve- information from both the brain as well as from our organs influence vagal tone. This means that how we’re feeling emotionally influences the body and how we work with our body influences how we feel. The perceived absence of threat, and a content emotional state leads to improved vagal tone, but also interventions targeting certain parts of our bodies influence vagal tone and the emotional state connected to it. We can make use of this bidirectional quality.
Here are 3 vagal tone interventions to try when you find your sympathetic nervous system in overdrive:
1 – Diaphragmatic breathing
Deep breathing exercises increase vagal tone (1). The diaphragm is linked to the brain via the vagal nerve. Take a moment to take long deep inhales through your nose counting to 10 – fill your lungs and extend your stomach while you breathe in. You can place one hand on your stomach for guidance. For the exhalation you want to take even more time slowly exhaling through your mouth. Repeat five to ten times. The effect is immediate relaxation and improved mental functioning. You can try measuring your pulse as you inhale and exhale. You might notice that every time you exhale your heartbeat slows down indicating the relaxing effect that is induced by the release of the neurotransmitter acetylcholine, the historically so-called vagusstoff (= German for vagus substance).
2 – Tend and befriend
The “tend and befriend” response is another parasympathetic response and it is both triggered by and leads to micro-moments of social connectedness (4). It can be understood as an upward spiral (3). You can activate this response by engaging in prosocial behaviours- in other words, doing something nice for someone else. Check in with a friend, give a gift, a hug, take time to listen, and so on. The interesting part is that this behaviour doesn’t have to target a friend but could be directed at a stranger or even someone who has hurt you. You can also approach this in a cognitive manner by engaging in Loving-Kindness meditation. In this type of meditation you think about others and yourself in a kind, loving and compassionate way. Meditation is an evidence-based technique to activate your parasympathetic response and you can find endless resources in the form of guided meditations online.
3 – Cold exposure
This method is among my personal favourites. Exposure to acute cold improves vagal tone (1). Evidence shows that when done regularly cold exposure lowers your sympathetic activation and increases parasympathetic response. You can expose yourself to cold by taking a cold shower of at least 30 seconds. If you live close to the sea you can also take a dip in the cold water, and if you dare and your health allows, you can keep this habit up throughout the seasons.
While these methods are valuable to help us regulate our nervous system, it is crucial to pay attention to the cause- why our sympathetic nervous system may be overly activated in the first place. This may for example be due to trauma or unhelpful thought patterns. Psychotherapy can help address these underlying issues.
(1) De Oliveira Ottone, V. et al. (2014). The effect of different water immersion temperatures on post-exercise parasympathetic reactivation. PLoS One, 1, 9(12).
(2) Gerritsen, R., & Band, G. (2018). Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity. Frontiers in human neuroscience, 12, 397.
(3) Kok, B. E. et al. (2013). How Positive Emotions Build Physical Health: Perceived Positive Social Connections Account for the Upward Spiral Between Positive Emotions and Vagal Tone. Psychological Science.
(4) Petrocchi, N. & Cheli, S. (2019). The social brain and heart rate variability: Implications for psychotherapy. Psychol Psychother, 92(2), 208-223.