Pranayama

Breath control in the Yogasūtra

A Sahapedia entry on prāṇāyāma reports that Patañjali's Yogasūtra defines breath control as stopping the flow of inhalation and exhalation (sūtra 2.49). It describes the practice as external, internal or stopped and regulated by place, time and number (2.50), and says mental steadiness may also result from exhalation and retention of breath (1.34). A systematic review of controlled trials describes the Yogasūtra as placing pranayama as the fourth of eight limbs of yoga. None of the sources reviewed for this page dates the Yogasūtra.

A neurophysiological review states that Patañjali names no specific breathing technique. Named techniques appear in later haṭha yoga texts, which the same review summarizes as listing eight kumbhakas (breath-retention practices).

Haṭha yoga texts and their dating

The Sahapedia entry dates the Haṭhapradīpikā to the fifteenth century and says it treats breath control with retention as key to mastering physical yoga. It reports that the text teaches eight prāṇāyāma techniques, all called kumbhakas: ujjāyī, bhastrikā, bhrāmarī, śītalī, śītkārī, sūryabheda, mūrcchā and plāvinī. The same entry dates the Gheraṇḍasaṃhitā to the eighteenth century and cites it for a fire-breath practice called agnisāra or vahnisāra.

These dates come from one encyclopedia-style entry. The sources reviewed do not discuss scholarly disagreement over dating, so they should be read as approximate and confirmed against specialist editions.

The word and its parts

A systematic review describes pranayama as a Sanskrit compound of prāṇa, glossed as breath of life or vital energy, and āyāma, glossed as expansion, regulation or control. The Sahapedia entry adds that āyāma can mean extension but mostly means restraint in yogic texts, which explains why translations vary between breath control, regulation and extension of the breath.

The same review lists four aspects of the breathing process in the practice: inhalation, exhalation, internal breath retention and external breath retention. A neurophysiological review uses the Sanskrit terms pūraka, recaka and kumbhaka for inhalation, exhalation and retention.

Overlap with slow breathing and other breathing exercises

Research on slow breathing uses a physiological definition: a narrative review puts it at 4 to 10 breaths per minute, against a typical 10 to 20, and a systematic review uses fewer than 10. Pranayama is not the same category, because it includes fast techniques such as kapālabhāti and bhastrikā and breath retention. A trial-level review classes nāḍī śodhana, ujjāyī and śītalī as slow and kapālabhāti and bhastrikā as fast.

Cochrane reviews group yogic breathing with Buteyko, Papworth and diaphragmatic breathing under breathing exercises, so evidence for that wider label does not map onto pranayama alone.

Named techniques at overview level

Reviews describe pranayama as deliberate modification of the breathing process, such as rapid diaphragmatic breathing, slow deep breathing, alternate nostril breathing and breath retention, usually done seated. Nāḍī śodhana is alternate nostril breathing. Kapālabhāti is described as active exhalation by rapid abdominal contraction with passive inhalation, and bhastrikā as forceful inhalation and exhalation.

Bhrāmarī is described as a buzzing, bee-like sound made on a nasal exhalation. Ujjāyī and śītalī appear in the traditional list of eight kumbhakas. Teaching details vary between schools, and this page does not give instructions or ratios.

How it appears in studies

In trials, pranayama is usually a bundle of techniques. The 18 controlled trials in one systematic review used practice periods from 4 days to 6 months, and many combined several techniques in daily sessions. Among six trials of pranayama for mental disorders, a protocol of nāḍī śodhana, ujjāyī, kapālabhāti and retention was tested alongside Sudarśan Kriyā Yoga, which featured in most of the publications.

Because techniques, durations and teachers differ between trials, a result from one protocol cannot be assumed for another technique that shares the same name, and the reviews do not standardize how sessions are taught.

Traditional and proponent claims

Sources describe the traditional rationale as a link between breath and mind. A neurophysiological review states that, according to the ancient yoga tradition, breath and mind are closely interconnected, and the Yogasūtra connects exhalation and retention with mental steadiness. The Haṭhapradīpikā is reported to treat breath control as key to mastering physical yoga.

Reviewers of the modern literature cite stress relief, cardiovascular effects, improved respiratory function and enhanced cognition as proposed benefits. None of the sources reviewed tests traditional concepts such as prāṇa or subtle channels.

Conditions and outcomes researchers have targeted

Controlled trials of pranayama have studied bronchial asthma, chronic obstructive pulmonary disease, pleural effusion, cancer-related fatigue and quality of life, anxiety in cardiac patients, and hypertension. More recent reviews cover heart rate and blood pressure in hypertension, symptoms in post-traumatic stress disorder and depression, and slow breathing for stress.

Reviews of pranayama trials

A systematic review searched to mid-2017 found 18 controlled trials of pranayama (13 randomized, 16 to 160 participants), mostly in India. Quality was rated poor in six, fair in seven and good in five, and heterogeneity prevented meta-analysis. A review of Bhrāmarī pranayama found six studies, none randomized, with very low methodological quality.

Blood pressure and heart rate

A 2026 meta-analysis of seven randomized trials (683 people with hypertension) reported lower heart rate (pooled standardized mean difference -0.43, five trials). Systolic and diastolic effects were not significant under random-effects models and heterogeneity was very high. One trial had low risk of bias, three some concerns and three high risk, with no certainty grading. NCCIH reports a modest blood pressure reduction for slow breathing in a review with high risk of bias and short follow-up.

Mental health and asthma

A 2025 meta-analysis of six randomized trials (517 patients with post-traumatic stress, depression or mixed non-psychotic disorders) found a small short-term symptom reduction against passive controls (standardized mean difference -0.27, 95% confidence interval -0.52 to -0.03). Four trials had high risk of bias, and the authors state it should not replace standard therapies. A Cochrane review of 22 trials (2,880 adults with mild to moderate asthma) found moderate-certainty quality-of-life gains at three months, but most trials tested yoga and adverse effects were not assessed.

Physiology of slow breathing

A systematic review of 15 studies in healthy people found slow breathing associated with higher heart rate variability and respiratory sinus arrhythmia, more EEG alpha and less theta power. A narrative review reports that heart rate variability peaks near six breaths per minute and that mean blood pressure may fall, while mechanisms remain debated. These are short-session findings in healthy volunteers, not trial evidence for pranayama in disease.

Adverse events in trials and case reports

In a 2023 trial summarized in the mental-disorders meta-analysis, 15 patients in the pranayama group reported minor adverse events, including anxiety, breathlessness, cough, dizziness, headache and flashback, mostly linked by the authors to kapālabhāti. Three serious events were judged probably unrelated. The meta-analysis found adverse events more frequent with fast than slow techniques and reporting insufficient.

A review of yoga case reports found four involving pranayama or yoga breathing, among 76 cases: pneumothorax after kapālabhāti, pneumomediastinum after a forceful Valsalva exercise, a rectus sheath hematoma and raised muscle enzymes, with one older fatal pneumomediastinum case its authors call atypical. Case reports cannot estimate frequency, and the authors advise beginners to avoid forceful breathing.

Cautions for specific conditions

A narrative review states that breath retention can raise systolic, diastolic and mean arterial pressure, and calls it contraindicated in hypertension, heart disease and recovery from illness, surgery or injury. It also says fast bhastrikā may be unsafe in hypertension and cardiovascular disease. These are the authors' statements in a review with small, uncontrolled evidence. The pranayama systematic review notes a kapālabhāti pneumothorax report and suggests supervision for people with compromised lung function.

NCCIH reports rare cases of relaxation techniques causing or worsening symptoms in people with epilepsy, certain psychiatric conditions or a history of trauma, without singling out breathing. The mental-disorders meta-analysis excluded psychotic disorders, and the one psychosis case in the yoga case-report review involved hot yoga, not breathing. The sources reviewed do not address pregnancy.

Historical warnings, training and care

The Haṭhapradīpikā (2.15 to 2.16) is reported to say that breath must be controlled step by step, otherwise it kills the practitioner, and the twelfth-century Amanaska criticizes hundreds of retentions as causing disease. No source reviewed describes a training standard or register specific to pranayama teaching. Chest pain, fainting or severe breathlessness are reasons to seek medical care, and breathing practice is not a replacement for assessment or prescribed treatment.