The Vagus Nerve

There’s a nerve in your body that behaves less like a wire and more like a diplomat. It negotiates between brain and body, emotion and organ, thought and heartbeat. It’s called the vagus nerve—named from the Latin for “wandering,” because it meanders from your brainstem through your neck, into your chest, and down into your abdomen. It touches your heart, lungs, stomach, even parts of your intestines. It is long. It is influential. And most people have never heard of it.

The vagus nerve is the star player of the parasympathetic nervous system—the branch responsible for “rest and digest.” When it’s active, your heart rate slows, digestion improves, inflammation decreases, and you feel calmer. Think of it as the brake pedal to the stress system’s accelerator. Stress (the sympathetic nervous system) says: run. The vagus nerve says: you’re safe now. Breathe.

Here’s where it gets philosophically strange. The vagus nerve doesn’t just respond to your thoughts—it shapes them. Signals don’t only travel from brain to body; about 80% of vagal fibers send information upward, from body to brain. Your gut, your heart rhythm, your breathing patterns—these feed into how you experience emotion. That “gut feeling” isn’t metaphorical poetry. It’s neural traffic.

Researchers talk about “vagal tone,” which basically means how efficiently your vagus nerve can activate the calming response. Higher vagal tone is linked to better emotional regulation, social connection, and resilience under stress. Slow breathing, humming, chanting, cold exposure, even certain forms of meditation appear to stimulate it. You can, to some degree, train your nervous system like a muscle.

The deeper lesson is humbling. We like to imagine ourselves as rational pilots steering a biological machine. But much of what we call mood, calmness, or anxiety is an emergent property of nerve signals humming below awareness. Your nervous system is not a background system—it is the stage on which your thoughts perform. And sometimes, the most intellectual act is simply to slow your breath and let the conductor reset the tempo.