Slow Breathing Systematic Reviews Summarized

What this page covers

A systematic review gathers all the studies on a question that meet set rules, so one study does not mislead. This page summarizes the reviews we could read on slow breathing. It is information only, not medical advice, and it is not a how-to. If breathing practice ever makes you dizzy, tingly, faint or more anxious, stop and return to normal breathing. In the United States, call 911 for an emergency. Breathing exercises are at most an add-on: never change or stop a medicine because of what you read here.

Many people hear "slow breathing" and think of one technique. In research it is a family of practices that share one feature: a lower breathing rate. One review defined slow breathing as fewer than 10 breaths per minute and looked at its effects in healthy people. [1] Trials rarely hide from participants which breathing they are doing, so expectations can shape self-reported results. See how breathing research is done.

What the reviews found, in one table

1. Does slow breathing change heart rate variability (HRV)?

   Established as a short-term physiological change; not a health outcome

   A review of 223 studies found higher vagally mediated HRV during and after slow breathing [2]

2. Does it change mood in healthy people?

   Promising but limited; short-term, self-reported

   A review of 15 studies reported more comfort and relaxation and less anxiety and anger [1]

3. Does it lower blood pressure?

   Mixed

   A review of 17 trials found a modest drop, with high heterogeneity [3]; a review of blinded, sham- or music-controlled device trials found no significant drop [4]

4. Does it ease acute pain?

   Insufficient evidence

   Seven trials; very low certainty evidence that pain may fall [5]

5. Does it help spinal pain?

   Promising but limited

   Low certainty evidence of less pain when added to other care [6]

Heart rate variability: the most consistent finding

HRV is the natural beat-to-beat variation in heart rate. The largest review we read pooled 223 studies and found HRV indices linked to the vagus nerve rose during slow breathing, right after one session, and after multi-session programs. [2] Its authors suggested slow breathing could be advised as a low-tech, low-cost adjunct, with few adverse effects expected. [2] An earlier review of 15 studies reported the same direction, along with changes in brain-wave patterns. [1]

What this does not show: that higher HRV from breathing prevents or treats disease. The authors of one review described their explanation of the mechanism as a hypothesis. [1] Another review of mechanisms noted that the processes behind these effects are multiple and complex. [7] For the physiology, see vagal tone, HRV and respiratory sinus arrhythmia.

Blood pressure: modest in some reviews, null in others

A 2019 meta-analysis pooled 17 trials in people with hypertension, prehypertension or on blood pressure medicine. It reported systolic pressure about 5.6 mmHg lower and diastolic about 3 mmHg lower, with high heterogeneity, meaning the trials disagreed with each other. [3] The U.S. National Center for Complementary and Integrative Health (NCCIH) notes the studies differed in design, had short follow-up and had high risk of bias. [8]

A stricter analysis looked only at blinded trials with an active comparison (a sham device or music). Five studies were suitable, and it found no significant lowering of office blood pressure, with short follow-up in every trial. [4] A 2022 review of device-guided slow breathing against usual care also found no significant reduction. [9] Details are on slow breathing and blood pressure. The honest summary is mixed: a small effect may exist, but better-controlled trials have not confirmed it. High blood pressure needs medical care; breathing practice does not replace it.

Pain

For acute pain in adults, a review found seven randomized trials, five with low risk of bias, but only very low certainty evidence that slow deep breathing may reduce pain intensity. [5] For spinal pain, a 2025 review of 20 studies (814 participants) found low certainty evidence that slow deep breathing reduced pain when added to other treatment. [6] See breathing exercises for pain.

Stress and everyday use

A review summarized by NCCIH found preliminary evidence that diaphragmatic breathing may help reduce stress. [8] The broader picture is on breathing exercises for stress.

Limits to keep in mind

• Reviews of healthy volunteers do not tell us what happens in illness. [1]
• Many findings are short-term. NCCIH points out the reviews did not examine long-term health outcomes such as stroke or heart attack. [8]
• Reviews mix different breathing patterns, devices and session lengths, which is why results vary.
• Relaxation techniques are generally considered safe for healthy people, though NCCIH says they may cause or worsen symptoms in some people, such as those with epilepsy, certain psychiatric conditions or a history of trauma. [8]