Can You Measure Vagal Tone?

The most precise metric for assessing vagal tone is heart-rate variability (HRV), says functional-medicine ­provider Navaz Habib, DC. A healthy heartbeat is not perfectly symmetrical; the rhythm varies slightly as the sympathetic and parasympathetic systems engage in a dynamic push and pull. HRV measures the time between individual heartbeats.

High HRV (more variance between heartbeats) corresponds to greater vagal tone, while low HRV suggests an overactivated sympathetic response and lower vagal tone. A number of large studies indicate that a robust HRV is predictive of a range of positive health outcomes, including a lower risk of type 2 diabetes and heart disease. It also corresponds to sharp cognition and emotional regulation.

Many devices on the market measure HRV, including watches, chest straps, and even rings to track trends and patterns. But there are also several tech-free ways to dial into your vagal tone.

One is the palatine-arch response test. The ability to lift the soft palate is directly linked to the effective function of the vagus nerve. Try depressing your tongue with a toothbrush and looking at the uvula in the back of your throat in a mirror. Observe how the arches framing your uvula move as you say, “Ahh.”

Ideally, the arches lift symmetrically, and the uvula points straight down. If the arches don’t rise or rise unequally, or the uvula points toward one side, it can indicate vagus nerve impairment.

If the vagus nerve can’t effectively lift the soft palate, your voice may have a nasal or monotone quality — another indicator of poor vagal tone.

The most accessible window into vagal tone is simply checking in with how you feel. In general, can you meet the demands of your day and then let them go? Or do you find yourself ruminating, feeling simultaneously tired and wired, and struggling to self-soothe?

“At its core, a regulated nervous system is a resilient nervous system,” explains somatic therapist Anna Ferguson, CCATP, in The Vagus Nerve Reset. “Burnout, illness, and chronic pain are all manifestations of a stressed nervous system.”