Unilateral Nostril Breathing: What the Research Shows

Quick answer: unilateral nostril breathing means breathing through one nostril while gently closing the other. A small group of studies from 1989 to 2004 tested whether this changes thinking, heart activity or early brain responses. They found measurable short-term effects in small samples, but the results are not consistent enough to say that one nostril reliably "activates" one side of the brain.

This page brings together four studies we previously summarised on separate pages, so that readers can see the research side by side rather than in isolated fragments.

What Is Unilateral Nostril Breathing?

In yoga, breathing through the right nostril is linked with Pingala nadi and an energising quality, and breathing through the left nostril with Ida nadi and a calming quality. Practices such as Surya Bhedana (right-nostril inhalation) and Chandra Bhedana (left-nostril inhalation) are built on this idea, while Nadi Shodhana alternates between the two sides.

Researchers became interested because the nasal cycle, the natural shift of airflow dominance from one nostril to the other over a few hours, appeared to track changes in nervous system activity. The question was whether deliberately breathing through one side could produce similar shifts.

The Four Studies

1. Cognitive performance in men and women (Block et al., 1989)

Block RA, Arnott DP, Quigley B, Lynch WC. Unilateral nostril breathing influences lateralized cognitive performance. Brain and Cognition. 1989;9(2):181-90.

Volunteers completed verbal and spatial tasks while breathing through one nostril. The effect of which nostril was open depended on sex: men and women showed different patterns, so the study did not support a simple rule that one nostril improves one type of thinking for everyone.

2. Forced nostril breathing and spatial tasks (Jella and Shannahoff-Khalsa, 1993)

Jella SA, Shannahoff-Khalsa DS. The effects of unilateral forced nostril breathing on cognitive performance. International Journal of Neuroscience. 1993;73(1-2):61-8.

In 51 right-handed university students (25 men and 26 women), spatial task scores were higher during left-nostril breathing in both sexes. Verbal scores were slightly higher during right-nostril breathing, but that difference was not statistically significant.

3. Forced nostril breathing and the heart (Shannahoff-Khalsa and Kennedy, 1993)

Shannahoff-Khalsa DS, Kennedy B. The effects of unilateral forced nostril breathing on the heart. International Journal of Neuroscience. 1993;73(1-2):47-60.

Across three small experiments (seven volunteers, then repeated trials with a single volunteer), heart rate was higher during right-nostril breathing. Left-nostril breathing was linked with a larger end-diastolic volume, meaning the heart filled with more blood before each beat. The results fit the traditional description of right-nostril breathing as more activating, but the samples were very small.

4. Right-nostril yoga breathing and auditory brain responses (Raghuraj and Telles, 2004)

Raghuraj P, Telles S. Right uninostril yoga breathing influences ipsilateral components of middle latency auditory evoked potentials. Neurological Sciences. 2004;25(5):274-80.

In 14 young men, right-nostril yoga breathing increased the size of two early brain responses to sound (the Na and Nb waves of middle latency auditory evoked potentials) on the right side, compared with a breath-awareness control. This suggests the practice can influence early sensory processing, although the practical meaning of such changes is unclear.

What the Research Can and Cannot Tell Us

• All four studies were small, short and conducted in specific groups, so the findings may not apply to everyone.
• Effects were measured during or straight after practice. They do not show lasting change.
• Results do not fit one neat left-brain and right-brain story, and some findings differed by sex.
• The studies support the idea that breath pattern affects the nervous system, which is consistent with wider research on slow and paced breathing.

How to Practise Safely

1. Sit upright and comfortably. Rest your left hand in your lap.
2. Use the right thumb to close the right nostril, or the ring finger to close the left. Press lightly; do not squeeze.
3. Breathe slowly and quietly through the open nostril. There is no need to force the breath, even though some studies used forceful breathing.
4. Start with two to three minutes, then return to normal breathing and notice how you feel.

Choose left-nostril breathing when you want to settle, and right-nostril breathing when you want to feel more alert. Avoid the practice when your nose is blocked, and stop if you feel dizzy, anxious or short of breath. If you have a heart condition, high blood pressure or a breathing disorder, check with your doctor before practising, especially with right-nostril or forceful breathing.

Related Practices and Research

For practice instructions, see Nadi Shodhan Pranayama, Surya Bhedan Pranayama and our complete guide to Pranayama. For related research, see Breathing Through a Particular Nostril Can Alter Metabolism and Autonomic Activities and Physiological Measures of Right Nostril Breathing.

Frequently Asked Questions

Does breathing through the left nostril activate the right side of the brain?

Some studies found effects that fit this idea, but others did not, and results differed between men and women. It is better to think of one-nostril breathing as a way to shift your overall state than as a switch for one brain hemisphere.

Is unilateral nostril breathing the same as Nadi Shodhana?

No. Nadi Shodhana alternates between nostrils on each breath. Unilateral nostril breathing uses only one side for the whole practice.

How should readers use this research?

Use it as informed context rather than a treatment plan. The studies are encouraging, but they are too small to support health claims on their own.

Medical Disclaimer

This article is for educational purposes only and does not provide medical advice, diagnosis, or treatment. Research summaries should not replace care from a qualified healthcare professional. If you have symptoms or a diagnosed condition, seek individualized medical guidance.