Academy
Autonomic nervous system

Vagus nerve and vagal tone

The vagus nerve is the body’s main “rest and restore” nerve – it connects the brain to your internal organs. Higher vagal tone (how active this calming nerve is) is linked to better heart-rate variability (HRV – the natural variation in time between heartbeats), lower inflammation, deeper sleep, better digestion, and a steadier mood. You can train it – it isn’t something fixed for life.

  • Helps regulate the heart, lungs, digestion, inflammation, and mood
  • HRV (heart-rate variability) is a direct sign of vagal tone
  • You can train it in 5–15 minutes a day, with changes measurable in 4–8 weeks
Rahulik hingamisharjutus – vagaalse toonuse tõstmine

What is the vagus nerve?

The vagus nerve is the tenth cranial nerve – the longest and most branched nerve in your autonomic nervous system (the system that controls automatic body functions). It runs from the brainstem, down through the neck and chest, and into the abdomen, connecting to the heart, lungs, stomach, gut, liver, and pancreas.

About 80% of the vagus nerve’s fibers carry information from your organs up to your brain. Only 20% carry signals the other way. This is why the vagus nerve is the main “gut-brain” pathway – it’s a big reason why digestion and heart activity affect mood, focus, and how well you handle stress.

Vagal tone describes how strongly the vagus nerve activates your body at rest. High vagal tone means a healthy balance in your nervous system, with the calming “rest and digest” mode dominant at rest. Low vagal tone means your body stays in a stress response too often, which is linked to worse sleep, digestion, inflammation, and mood.

Signs of low vagal tone

  • Ongoing fatigue and feeling “wired but tired” even after resting
  • Poor sleep – your mind won’t switch off at night
  • Digestive issues: bloating, constipation, IBS-type symptoms
  • Frequent colds and slow recovery from illness
  • Anxiety, inner restlessness, or panic attacks
  • Low HRV (heart-rate variability) – under 30 ms on a tracker
  • High resting heart rate (over 75 beats per minute)
  • Getting emotionally upset easily over small things
  • Feeling cold easily, with cold hands and feet
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HRV ja autonoomse tervise näitajad

Puhkeoleku näitajad täiskasvanul (parim on mitme päeva keskmine)

HRV RMSSD (25–35a)

Optimaalne
> 60 ms
Keskmine
35–60 ms
Nõrk
< 35 ms

HRV RMSSD (36–50a)

Optimaalne
> 45 ms
Keskmine
25–45 ms
Nõrk
< 25 ms

HRV RMSSD (51–65a)

Optimaalne
> 35 ms
Keskmine
20–35 ms
Nõrk
< 20 ms

Puhkepulss

Optimaalne
50–65 lööki/min
Keskmine
65–75 lööki/min
Nõrk
> 75 lööki/min

Hingamissagedus (puhkus)

Optimaalne
8–12 /min
Keskmine
12–18 /min
Nõrk
> 18 /min

Ortostaatiline pulsitõus

Optimaalne
< 15
Keskmine
15–25
Nõrk
> 25

HRV väärtused varieeruvad päevast päeva. Trend on olulisem kui üksik mõõtmine. Nutikelladest saadud RMSSD ja koherentsiskoor on head jälgimisvahendid.

Frequently asked questions

Teaduslikud allikad

  1. Porges SW. The polyvagal theory: new insights into adaptive reactions of the autonomic nervous system. Cleveland Clinic Journal of Medicine, 2009. doi.org/10.3949/ccjm.76.s2.17
  2. Thayer JF, Lane RD. Claude Bernard and the heart-brain connection. Neuroscience & Biobehavioral Reviews, 2009. doi.org/10.1016/j.neubiorev.2008.08.004
  3. Bonaz B et al. Vagus Nerve Stimulation: from Epilepsy to the Cholinergic Anti-inflammatory Pathway. Neurogastroenterology & Motility, 2013. doi.org/10.1111/nmo.12076
  4. Laborde S et al. Effects of slow-paced breathing on heart rate variability: a systematic review. Psychophysiology, 2022. doi.org/10.1111/psyp.14020
  5. Kok BE et al. How positive emotions build physical health via the vagus nerve. Psychological Science, 2013. doi.org/10.1177/0956797612470827
  6. Tyagi A, Cohen M. Yoga and heart rate variability: A comprehensive review. International Journal of Yoga, 2016. doi.org/10.4103/0973-6131.183712
  7. Breit S et al. Vagus Nerve as Modulator of the Brain-Gut Axis in Psychiatric and Inflammatory Disorders. Frontiers in Psychiatry, 2018. doi.org/10.3389/fpsyt.2018.00044
Clinical experience

Dr Sergey Saadi – expert in autonomic health and anti-inflammatory medicine

Dr Sergey Saadi is a physician with over 15 years of clinical practice.

  • Clinical approach: HRV + inflammatory markers + sleep audit
  • Regular speaker in media and in clinician training
  • Author of “Dangerous secrets of blood sugar” (Varrak)

This page is educational and general. It is not personal medical advice, a diagnosis or a treatment plan. Discuss changes with your doctor.

Doctor's appointments

Dr Sergey Saadi sees patients at Synage Clinic

Appointment times and services are listed on the clinic's website. The clinic is a separate company from the Academy.

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