The Vagus Nerve: Your Brain's Stress Reset Switch— and How to Use It

By Dr. Prerna Kohli  |  Clinical Psychologist, Gurugram  |  Updated June 2026

Written by Dr. Prerna Kohli, PhD

Dr. Kohli is one of India's leading clinical psychologists, based in Gurugram. She integrates neuroscience-informed approaches into her clinical practice, helping patients understand the biological foundations of their mental health alongside the psychological ones— and giving them practical tools they can use every day.

In my years of clinical practice, I have observed something consistent: people who struggle with chronic anxiety, persistent low mood, or emotional dysregulation are frequently people whose nervous systems have become stuck in a state of chronic activation. They are perpetually on alert— scanning for threat, unable to fully relax, exhausted by the effort of managing their own internal state.

The vagus nerve sits at the centre of this pattern. Understanding it— and learning to work with it— gives patients a tangible, evidence-based tool for shifting their own physiology. That shift creates space for psychological work to take root.

What Is the Vagus Nerve? A Plain-Language Explanation

The vagus nerve— from the Latin for "wandering"— is the tenth cranial nerve and the longest nerve in the autonomic nervous system. It originates in the brainstem and meanders through the neck, chest, and abdomen, connecting the brain to the heart, lungs, oesophagus, stomach, intestines, liver, kidneys, and more.

It is the primary pathway of the parasympathetic nervous system— the system responsible for the body's rest-and-digest state, as opposed to the sympathetic nervous system's fight-or-flight state. When the vagus nerve is active and well-toned, it applies a gentle braking force on the stress response, helping the body return to baseline after a threat has passed.

A crucial and often surprising fact: approximately 80% of the nerve fibres in the vagus nerve carry information upward— from the body to the brain— rather than downward. This means the vagus nerve is primarily a reporting system, constantly updating the brain on the state of the body's organs. This bottom-up communication is why physical states so powerfully shape mental states— and why physical interventions can shift psychological ones.

Vagal Tone: What It Is and Why It Matters

Vagal tone refers to the baseline activity level of the vagus nerve— essentially, how effectively it is doing its job of regulating the body's stress response and organ function.

High vagal tone is associated with emotional resilience, good heart rate variability, effective digestion, low systemic inflammation, and the ability to recover quickly from stress. People with high vagal tone tend to be calmer under pressure, more empathetic, better at sustaining attention, and more emotionally stable.

Low vagal tone is associated with chronic anxiety, depression, difficulty regulating emotions, poor digestive health, elevated inflammation markers, impaired immune function, and cognitive difficulties including brain fog and poor working memory. It is also associated with social withdrawal and reduced capacity for connection— which further compounds psychological distress.

The Vagus Nerve and Mental Health: Four Key Connections

1. Stress Response Regulation

The vagus nerve is the primary mechanism by which the body returns to baseline after a stress response. When you perceive a threat— real or imagined— the sympathetic nervous system activates: heart rate rises, breathing quickens, digestion slows, muscles tense, cortisol floods the system. The vagus nerve is what applies the brake on this cascade once the threat has passed. In people with low vagal tone, this brake is weak— meaning the stress response persists longer than necessary, and the body spends more time in a physiologically activated state than is healthy.

2. Mood Regulation via the Gut-Brain Axis

The gut and brain are in constant bidirectional communication via the vagus nerve— a connection now referred to as the gut-brain axis. The gut contains over 100 million neurons and produces approximately 90% of the body's serotonin. The vagus nerve carries signals from this enteric nervous system directly to the brain. Disruption of this pathway— through poor gut health, dysbiosis, or low vagal tone— directly impacts mood, anxiety levels, and emotional regulation. This is one reason why chronic digestive problems so frequently co-occur with anxiety and depression.

3. Inflammation Control

The vagus nerve has a direct anti-inflammatory role, suppressing the production of pro-inflammatory cytokines through what is called the cholinergic anti-inflammatory pathway. Chronic low-grade inflammation is now recognised as a significant contributor to depression, cognitive decline, and fatigue. Poor vagal tone means this anti-inflammatory mechanism is underactive— allowing inflammation to persist at levels that directly affect brain function and mood.

4. Cognitive Function and Memory

Vagal activity has been shown to influence the release of norepinephrine in the brain, particularly in the hippocampus— the region most critical for learning and memory consolidation. Higher vagal tone is associated with better attention, improved working memory, and faster cognitive processing. Lower vagal tone correlates with the cognitive sluggishness, poor concentration, and forgetfulness that so many people living with chronic stress report.

8 Evidence-Based Ways to Stimulate Your Vagus Nerve Daily

The following techniques are all supported by research on vagal stimulation and are accessible without any equipment, specialist training, or cost. They work best when practiced consistently— daily, not occasionally.

What About Medical Vagus Nerve Stimulation?

You may have encountered references to clinical Vagus Nerve Stimulation (VNS)— a medically implanted device used in the treatment of drug-resistant epilepsy and, more recently, treatment-resistant depression. This is a specialist medical intervention, prescribed and monitored by neurologists and psychiatrists, and is entirely separate from the natural stimulation techniques described above.

For the vast majority of people reading this— those managing everyday stress, anxiety, low mood, or cognitive difficulties— natural vagal stimulation through the techniques above is the appropriate and effective intervention. If you have been formally diagnosed with a condition that has not responded to standard treatment, speak with your psychiatrist or neurologist about whether clinical VNS is relevant to your situation.

The Vagus Nerve and Psychological Therapy: A Complementary Relationship

One of the most important insights from modern neuroscience is that psychological therapy and physiological regulation work synergistically. Cognitive and behavioural interventions change how we think and what we do. Vagal stimulation techniques change the physiological environment in which that thinking and behaviour occurs.

When a person comes to therapy in a state of chronic sympathetic activation— heart racing, breathing shallow, unable to slow down— the window for cognitive work is narrow. The prefrontal cortex, responsible for rational thought and perspective-taking, is literally less accessible when the stress response is dominant. Vagal stimulation techniques help widen that window, creating the physiological conditions under which therapy can be most effective.

I regularly teach vagal stimulation techniques to patients as part of their broader therapeutic work— not as a replacement for psychological intervention, but as a foundation that makes everything else more possible.

Frequently Asked Questions

Your Nervous System Is Not Your Enemy— It Needs Training

Chronic stress, anxiety, and emotional dysregulation are not character flaws. In many cases, they are the predictable output of a nervous system that has been operating in high-alert mode for too long without adequate recovery. The vagus nerve is the lever through which we can begin to change that.

The techniques in this article are a starting point. Used consistently, they can shift the physiological baseline from which you navigate everything— your relationships, your work, your capacity to be present. But for those whose distress goes beyond what self-practice can address, professional support provides the deeper work that makes lasting change possible.