Vagus Nerve
The wandering nerve. The vagus nerve (Latin: "wandering") is the longest cranial nerve, running from brainstem to gut with branches to heart, lungs, and digestive organs. It's the main highway of the parasympathetic nervous system, controlling rest-and-digest functions. It's bidirectional—80% of fibers carry information FROM body TO brain. The gut-brain axis runs primarily through the vagus.
Vagus Nerve Functions
Heart Rate
Vagal brake slows heart. Higher vagal tone = lower resting heart rate. HRV marker.
Digestion
Stimulates gut motility. Enzyme secretion. "Rest and digest" function.
Inflammation
Cholinergic anti-inflammatory pathway. Reduces cytokines. Immune regulation.
Voice & Swallowing
Larynx control. Vocal cord movement. Swallowing reflex.
Breathing
Respiratory rate modulation. Breathing exercises activate it. Exhale emphasis.
Mood
Gut signals to brain. Serotonin production in gut. VNS for depression.
Vagal Tone
High Vagal Tone (Good)
- • Higher HRV
- • Better stress recovery
- • Lower inflammation
- • Good digestion
- • Emotional regulation
- • Resilience
Low Vagal Tone
- • Lower HRV
- • Chronic stress
- • Higher inflammation
- • Digestive issues
- • Anxiety, depression
- • Poor recovery
How to Stimulate Vagus Nerve
Slow Breathing
Long exhales activate vagus. 5.5 breaths/minute optimal. Coherent breathing.
Cold Exposure
Cold water on face (dive reflex). Cold showers. Wim Hof method.
Gargling/Singing
Vibrates vagus in throat. Humming, chanting. Om meditation.
Probiotics
Gut bacteria communicate via vagus. Lactobacillus strains studied.
Omega-3 Fats
DHA especially. Increases HRV. Anti-inflammatory.
Exercise
Regular moderate exercise. Improves vagal tone. Not overtraining.