Vagus Nerve
The wanderer. The vagus nerve ("vagus" = wandering) is the longest cranial nerve, running from brainstem to colon. It's the main conduit of the parasympathetic nervous system—controlling rest, digestion, and recovery. High vagal tone means resilience; low vagal tone underlies anxiety, inflammation, and poor digestion.
What the Vagus Nerve Controls
Heart Rate
Slows heart rate. "Vagal brake" on the heart. High vagal tone = lower resting HR.
Digestion
Stimulates stomach acid, bile, pancreatic enzymes, gut motility. "Rest and digest."
Inflammation
Cholinergic anti-inflammatory pathway. Vagus dampens cytokine production.
Voice & Swallowing
Controls larynx and pharynx. Hoarseness can indicate vagus issues.
Mood & Calm
Signals safety to brain. Low vagal tone linked to anxiety, depression, PTSD.
Gut-Brain Communication
80% of vagus fibers go FROM gut TO brain. Gut feelings are real.
Vagal Tone
High Vagal Tone
- High heart rate variability (HRV)
- Quick recovery from stress
- Good digestion
- Emotional regulation
- Lower inflammation
- Better sleep
Low Vagal Tone
- Low HRV
- Stuck in fight-or-flight
- Digestive problems (low acid, slow motility)
- Anxiety, depression
- Chronic inflammation
- Poor stress resilience
How to Stimulate the Vagus Nerve
Cold Exposure
Cold water on face, cold showers. Activates dive reflex → vagus activation.
Deep Breathing
Long exhales activate vagus. 4-7-8 breathing. Box breathing. Exhale longer than inhale.
Humming/Singing
Vagus innervates vocal cords. Humming, chanting "Om," gargling stimulate it.
Meditation
Regular practice increases vagal tone over time. Loving-kindness especially effective.
Social Connection
Positive social interactions activate vagus. Isolation reduces tone.
Exercise
Moderate exercise improves HRV. Don't overdo it—overtraining harms vagal tone.