What Is the Vagus Nerve?

The vagus nerve is the longest cranial nerve in the body. It’s called “vagus” because it wanders, like a vagabond, through the body, connecting the brainstem to the heart, lungs, stomach, intestines, and even parts of the face and ears. It carries messages back and forth, helping the brain keep tabs on what’s happening inside us.

Its Link to Interoception

One of the vagus nerve’s biggest jobs is supporting interoception which is part of the sensory system. It is our sense of what’s going on inside the body. Is the heart racing? Is the belly empty or full? Are the lungs breathing slowly or fast? The vagus nerve helps the brain interpret these messages and respond appropriately.

When the vagus nerve is working well, our children can feel and respond to hunger, thirst, bathroom needs, and big emotions. When it’s not, everything from potty training to meltdowns can get stuck.

Over or Underresponsive: What It Looks Like

Like everything in neurodevelopment, balance is the goal. The vagus nerve can be:

If the vagus nerve is underresponsive, the child can seem disconnected from body cues. They may not not feeling hunger (causing them to eat little) or fullness (resulting in constant eating), ignoring bathroom needs (difficulty with learning to use the toilet because they never feel the urge to go), or missing signs they’re becoming overwhelmed until they meltdown.

If the vagus nerve is overresponsive, a child may get stuck in fight, flight, or freeze. They may be easily startled, anxious, rigid, hit when overwhelmed, or run from a demand under stress. Their body might stay in a protective mode even when they’re safe. When a child feels physiologically unsafe, learning is impossible.

How This Shows Up in Our Children with Down Syndrome

In children with Down syndrome, we often see the vagus nerve working overtime or underpowered and we may see some things like:

• Constipation or digestive sluggishness (Disregarded as a consequence of low muscle tone)
• Poor saliva management or swallowing coordination
• Emotional reactivity that flips from calm to meltdown fast
• Sleep challenges
• Difficulty sensing when they need a break, drink, or snack (Or becoming incontinent when absorbed in an activity)
• Lashing out or running off
• Mutism when upset

This isn’t “bad behavior,” and it definitely isn’t “Just DS,“It’s a dysregulated nervous system.

5 Simple Ways to Support the Vagus Nerve

Here are a few gentle, everyday activities to help balance and strengthen the vagus nerve’s pathways:

1. Breathwork
Practice slow, big belly breaths together. Blow bubbles or pretend to blow up a balloon. Breathwork patterns like box breathing (Inhale for 4, hold for 4, exhale for 4, hold for 4).

2. Humming or Singing
The vibration in the throat stimulates the vagus nerve. Try humming, or chanting “Om.”

3. Sounds
High violin content in classical music excites, and lor basal tones such as Gregorian chant or Baroque calms.

4. Rhythmic Rocking or Swinging
Gentle back-and-forth movement calms the nervous system and supports integration.

5. Gargling or Blowing Bubbles
Gargling activates the muscles around the vagus nerve. Little ones love blowing bubbles in a cup with a straw!