Nasal breathing, slow breathing and stress: what the research shows

Nasal breathing may help with stress, mostly as the usual route for slow breathing, which has the strongest evidence. Slow breathing consistently raises heart rate variability, a sign that the body's calming system is more active, and trials link breathwork to modestly lower stress and anxiety. Nose breathing itself has a smaller but encouraging body of research, including a small study that found lower diastolic blood pressure than mouth breathing.

What does slow breathing do to your body?

Slow breathing's clearest effect on your body is on heart rate variability (HRV), the natural variation in time between heartbeats. Some HRV measures reflect the parasympathetic nervous system, the branch that slows things down after stress.

A 2022 meta-analysis in Neuroscience & Biobehavioral Reviews pulled together 223 studies of voluntary slow breathing. It found increases in these parasympathetic HRV measures during slow breathing, immediately after a single session, and after programs that ran over several sessions. The authors described slow breathing as a low-tech, low-cost technique with few expected side effects.

A 2018 systematic review in Frontiers in Human Neuroscience looked at 15 studies of slow breathing, defined as fewer than 10 breaths a minute, in healthy people. Alongside higher HRV, the studies reported changes in brain activity and psychological effects. People felt more comfortable, relaxed and alert, with less anxiety, anger and confusion.

Does breathwork lower stress?

Breathwork does seem to lower stress, with reasonable evidence for a modest effect.

A 2023 meta-analysis in Scientific Reports pooled 12 randomized trials that measured self-reported stress. Breathwork was linked to lower stress than control conditions, with what the authors called a small-to-medium effect. Separate analyses found similar effects on anxiety, across 20 trials, and on symptoms of depression, across 18 trials.

The authors were careful. The trials had a moderate risk of bias, and they urged caution so the hype doesn't run ahead of the evidence. That's a fair way to read it: a helpful tool, not a cure for stress. It also means the effect you get may be modest. The trials compared breathwork with control conditions that didn't involve breathwork, so they say more about whether breathwork helps than about which technique is best. Different trials used different exercises, for different lengths of time, in different groups of people.

One trial gives a sense of how little time it can take. In a 2023 study from Stanford published in Cell Reports Medicine, people did five minutes a day of one of three breathing exercises or mindfulness meditation for a month. Cyclic sighing, which focuses on long, slow exhales, gave greater improvements in mood and a larger drop in breathing rate than meditation.

Where does nasal breathing come in?

Most of the slow breathing research doesn't compare nose and mouth directly. The 2018 review noted that not every study specified the route, but it's plausible that most slow breathing techniques are done through the nose. The authors went further and proposed that receptors inside the nose may be one of the ways slow breathing affects the brain. They called for studies comparing slow breathing through the nose with breathing through the mouth.

A few studies have started to look at the nose itself.

In a 2023 study in the American Journal of Physiology, 20 young adults breathed only through the nose and only through the mouth while resting. Nasal breathing was linked to slightly lower mean and diastolic blood pressure, with a median diastolic reading of 68 compared with 72 mmHg. It also gave a higher share of the parasympathetic component of HRV. Systolic blood pressure and heart rate didn't change. It's a small, short-term study in young people, but the direction fits with the slow breathing research.

A 2016 study in the Journal of Neuroscience recorded electrical activity from electrodes inside the brains of people with hard-to-treat epilepsy. Natural breathing synchronized activity in the smell cortex and in limbic areas, including the amygdala and hippocampus, which are involved in emotion and memory. These rhythms were strongest when breathing in, and they faded when breathing was switched from the nose to the mouth. In separate tests with healthy volunteers, the phase of breathing affected fear discrimination and memory recall. None of this shows that nose breathing lowers stress, but it does show the nose plays a part in how breathing connects to the brain.

How can you practice slow nasal breathing?

You can practice slow nasal breathing without special equipment. A simple approach that fits the research:

1. Sit or lie comfortably with your mouth closed and breathe in through your nose.
2. Slow your breathing to fewer than 10 breaths a minute. A count of four in and six out works out to six breaths a minute.
3. Let the exhale be longer than the inhale. That's the idea behind cyclic sighing in the Stanford trial.
4. Keep it short. The Stanford participants did five minutes a day.

If your nose feels too blocked to do this comfortably, start there. Our two-minute nose test is a quick check, and how to unblock your nose before bed has practical steps. For more exercises, see nasal breathing exercises, and for the bedtime version, slow breathing for sleep.

Can you stay a nose breather at night?

You can stay a nose breather at night, but it takes some help. During the day you can choose how you breathe. At night you can't, and plenty of people drift into mouth breathing while they sleep. If your nose is clear and your mouth still falls open, mouth tape is a simple way to keep your lips together so you keep breathing through your nose. How to start mouth taping walks through the first week, and nasal vs. mouth breathing covers why the nose is the better route during sleep.

Some people feel uneasy the first time they tape. A few minutes of slow nasal breathing with the tape on before you turn the light off may help you get used to it, and mouth taping anxiety has more tips.

The research on tape is still limited. A 2025 systematic review in PLOS One found 10 studies with 213 patients and warned of a potentially serious risk for people who tape with a blocked nose. Only tape when your nose is clear, and don't use it on children.

What are the limits of this research?

The main limit of this research is that most studies are small and short. The breathwork trials rely on self-reported stress, and blinding people to a breathing exercise is hard. The nose-versus-mouth studies so far measure body signals over minutes, not stress over weeks.

So the honest summary is this. Slow breathing has solid evidence for shifting the body toward a calmer state and modest evidence for lowering stress. Breathing through the nose is the natural way to do it and has early research of its own. If stress or anxiety is affecting your daily life, breathing exercises can sit alongside proper care from a doctor or therapist, not replace it.

If you want to try mouth tape, our pick is the Titan Bamboo Silk Mouth Tape.

Read next

• Slow breathing for sleep
• Nitric oxide and nasal breathing
• Does breathing through your nose improve sleep quality?

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.