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World Hypertension Day, and a 2025 clinical trial that named Anulom-Vilom

Patients stayed on their medication. They added ten minutes of alternate nostril breathing. The numbers came down anyway.

Breath Lab6 min readFirst researched 14 May 2026

Sunday is World Hypertension Day. The World Health Organization’s 2026 theme is “Controlling Hypertension Together: check your blood pressure regularly, defeat the silent killer.” Roughly 1.4 billion adults live with high blood pressure right now. About half do not know it. Of those who do, many are on medication that helps but does not fully resolve the problem.

This piece is about what a 2025 randomised controlled trial found when it added one specific breathing practice to standard care. The practice has a Sanskrit name. The trial named it explicitly.

The Trial

In 2025, a team led by Gauri Mittal at the All India Institute of Medical Sciences ran an exploratory randomised trial of Nadi Shodhan Pranayama as an adjunct to standard non-pharmacological management in patients with hypertension. The paper was published in Annals of Neurosciences (SAGE) and is now open access on PubMed Central as PMC11996816.

The protocol was simple. Patients in the intervention group practised two minutes of yogic deep abdominal breathing followed by ten minutes of Nadi Shodhan Pranayama, daily, for six weeks. All patients in the trial stayed on their antihypertensive medication throughout. The intervention sat on top of standard care, not in place of it.

The results were measured immediately after a single ten-minute session, and again after six weeks of daily practice.

After a single session, systolic and diastolic blood pressure both fell significantly compared to baseline. After six weeks, the reductions were larger, and heart rate variability autonomic parameters had also improved, indicating a measurable shift in the sympathetic-parasympathetic balance that underlies blood pressure regulation.

The paper notes that “Nadi Shodhan Pranayama” is the formal Sanskrit name, and that the same practice is commonly called Anulom-Vilom in everyday usage. Both names refer to the same thing: slow, controlled, alternate nostril breathing.

Why This One

The breathwork literature is large. What makes this trial unusual is the specificity. It was not a generic “slow breathing” study. It did not pool four different techniques into a single arm. The researchers named one practice, defined the timing and the technique, and measured what happened.

This matters because a 2026 paper in Psychiatry International (MDPI) compared specific breathwork techniques head-to-head and found that slow-paced nasal breathing patterns outperformed fast-paced patterns and mouth-breathing variants across autonomic and stress outcomes. A 2025 meta-analysis in Frontiers in Psychiatry of pranayama for mental health drew a parallel conclusion, noting that slow breathing produced fewer adverse events than fast breathing in clinical populations.

Slow nasal breathing is the family. Alternate nostril breathing is the specific structured form. The Mittal trial measured exactly that, in exactly the population (hypertensive patients on medication) that the WHO is asking the world to think about on Sunday.

What The Practice Actually Is

The mechanics are unambiguous. Sit upright. Close the right nostril with the right thumb. Breathe in slowly through the left nostril. Close the left nostril with the right ring finger, release the right thumb, exhale through the right nostril. Breathe in through the right nostril. Close the right nostril, release the left, exhale through the left. That is one round.

A trained beginner can complete a round in roughly thirty to forty seconds. Ten minutes is twenty rounds. Five minutes is ten.

There is no equipment, no subscription necessary, no body-modification practice involved. The technique is taught in basic yoga classes around the world and is one of the oldest structured breathing patterns in continuous practice, with formal description in Vedic texts dating back more than two thousand years.

Why The Effect Is Plausible

Two mechanisms get cited most often in the literature, and both line up with what the Mittal trial measured.

The first is autonomic. Slow nasal breathing at roughly five to six cycles per minute brings respiratory rate close to the resonance frequency of the cardiovascular baroreflex. Practiced for several minutes, it increases heart rate variability and shifts the sympathetic-parasympathetic balance toward parasympathetic dominance. Lower sympathetic tone, lower vascular resistance, lower blood pressure. The Mittal trial’s HRV findings are consistent with this.

The second is the alternate nostril element specifically. Nostril dominance is not random, it cycles, and which nostril is dominant correlates with which hemisphere of the brain is more active and with which branch of the autonomic nervous system is more engaged. Deliberately balancing the two sides of the breath, as Nadi Shodhan Pranayama does, has been hypothesised to balance the autonomic state. This is more speculative than the resonance-frequency story, but it is the part of the practice the trial actually tested, and the outcomes lined up with the prediction.

The Mittal paper does not over-claim either mechanism. It measures what it measures: blood pressure, before and after, single session and six weeks, with an intervention named specifically.

How To Use It

Two minutes of slow abdominal breathing, then ten minutes of alternate nostril breathing, daily for six weeks. That is the protocol the trial measured. If a daily ten-minute commitment is too much to start with, the literature on the resonance-frequency mechanism suggests that even five minutes of slow nasal breathing at five to six cycles per minute will move heart rate variability measurably. The Mittal trial measured the effect of a single ten-minute session, and it was statistically significant.

If you are on hypertension medication, this is an adjunct, not a replacement. Talk to your doctor before changing anything about your prescription. The trial added the practice on top of standard care, and that is the only thing it tested.

Why I Built A Timer For This

I built Anuloma Viloma Timer because the practice itself is free, ancient, and well-documented, but the one thing that consistently breaks beginners is counting. When you start out, you are tracking which nostril, which phase of the breath, and how long each phase has lasted. The cognitive load is high enough that the practice often unwinds the calm it is supposed to create.

The app times the four phases of one round (inhale, the optional hold after inhale, exhale, the optional hold after exhale), repeats them for the duration you set, and gets out of the way. It runs on iPhone and Apple Watch. There is a subscription tier with extra features, but the core practice timer is free and stays free.

The 2025 Mittal trial used a ten-minute Nadi Shodhan Pranayama practice. The Anuloma Viloma Timer is designed for exactly that.

Three Days From Now

World Hypertension Day is Sunday May 17, 2026. The WHO toolkit is live. The peer-reviewed evidence for one specific practice is now open access. The technique has been on the shelf for roughly two and a half thousand years.

If you have a doctor, talk to them about anything you change. If you have ten minutes a day for six weeks, the trial that named the practice measured what happened. Both numbers came down.

Anuloma Viloma Timer is free on the App Store. No subscription necessary.

Primary citation: Mittal G, Pathania M, Bhardwaj P, Dhar M, Khapre M, Mittal S. An Exploratory Randomised Trial to Assess the Effect of Nadi Shodhan Pranayama as an Adjunct Versus Standard Non-pharmacological Management in Hypertensives. Annals of Neurosciences, 2025. PMC11996816. https://pmc.ncbi.nlm.nih.gov/articles/PMC11996816/

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