This article is not telling you to stop taking blood pressure medication — let your doctor evaluate that. What I am inviting you to do is start changing how you breathe. You have to breathe anyway, so why not do it in a way that actively supports your health?
Many people live with the effects of high blood pressure, managing it through medication or lifestyle adjustments. What is less well known is that the way you breathe — through the nose or the mouth, shallowly or deeply — has a direct and measurable effect on blood pressure. The science behind this is solid, and the practice is something anyone can start today.
The Role of Nitric Oxide
When you breathe through your nose, the sinuses produce nitric oxide (NO) — a molecule with a powerful vasodilatory effect. Vasodilation means the blood vessels widen, blood flows more easily, and the heart does not have to work as hard. Regular nasal breathing helps maintain healthy nitric oxide levels, which supports a relaxed vascular system and lower blood pressure over time.
Studies have shown that nasal breathing increases nitric oxide levels in the blood by up to 20%, directly supporting better blood flow and reduced blood pressure (Lundberg et al., 1996). Mouth breathing bypasses the nasal passages entirely, cutting off this production and reducing the body’s natural capacity for vascular regulation.
Why CO₂ Is Not the Enemy
Carbon dioxide is often thought of as a waste product — something to be expelled as quickly as possible. In fact, CO₂ plays an essential role in keeping blood vessels open and blood pressure stable. Healthy CO₂ levels create a vasodilatory effect, relaxing the smooth muscle in blood vessel walls and allowing blood to flow more freely. This mechanism also supports efficient oxygen delivery to tissues.
Rapid or shallow breathing causes the body to expel too much CO₂, disrupting this balance. When CO₂ levels fall too low, blood vessels can constrict — which raises blood pressure. Slower, deeper breathing retains more CO₂, encourages vessel relaxation, and supports pressure reduction.
Research by Dempsey et al. (1984) demonstrated that controlled CO₂ levels contribute directly to vasodilation. Guyton and Hall’s Textbook of Medical Physiology further outlines CO₂’s role in relaxing smooth muscle in blood vessel walls and its contribution to blood pressure regulation.
Activating the Body’s Calming System
Slower, deeper breathing does more than support CO₂ balance — it directly activates the parasympathetic nervous system, the body’s rest and digest mode. When the parasympathetic system is engaged, heart rate drops, blood vessels relax, and blood pressure follows. This effect is well documented across numerous studies on slow, mindful breathing and cardiovascular health.
The vagus nerve is the primary pathway through which breathing influences the parasympathetic system. Slow nasal breathing stimulates vagal tone, which is associated with lower resting blood pressure, better heart rate variability, and greater overall resilience to stress.
Mouth Breathing vs. Nasal Breathing
Mouth breathing bypasses nitric oxide production, tends toward shallower breathing patterns, and is associated with the stress response — all of which elevate heart rate and blood pressure. Chronic mouth breathing has been linked to higher baseline blood pressure and increased risk of conditions such as obstructive sleep apnea, which further strains the cardiovascular system.
Nasal breathing, by contrast, encourages a slower and deeper rhythm, supports nitric oxide production, maintains healthier CO₂ levels, and calms the nervous system. Research indicates that nasal breathing can reduce exercise-induced blood pressure spikes and improve overall respiratory function (Swift et al., 2005).
For a deeper look at the science and practice of nasal breathing at night, see our post on mouth taping.
Practical Steps: Breathing for Blood Pressure Health
- Keep your mouth closed. Start noticing when you breathe through your mouth and gently close it. Making nasal breathing the default — during daily activities, exercise, and eventually sleep — is the single most accessible change you can make.
- Slow your breathing down. Longer, slower breaths increase CO₂ retention, support vasodilation, and activate the parasympathetic nervous system. Even a few minutes of deliberately slower breathing each day creates a measurable effect over time.
- Practise diaphragmatic breathing. Breathing deeply into the diaphragm rather than the chest promotes better CO₂ balance and cardiovascular relaxation. Lie on your back, place one hand on your belly, and breathe so that the belly rises on the inhale and falls on the exhale. Five to ten minutes before bed is a good starting point.
- Use a guided practice to build the habit. Our free Soma Breath course and the 11 Minutes to Peace meditation are both good entry points for introducing slower, intentional breathing into your daily routine.
Ready to Go Further?
Start with our free 11 Minutes to Peace Challenge — 11 minutes a day, a guided breathwork meditation, a Soma Breath introduction course, and email support to keep you on track. Free and open to anyone.
If you want to go deeper into the specific topics covered in this article, these three recorded workshops are directly relevant:
The CO₂ Advantage — Train Your Nervous System for Calm, Clarity and Energy — a deep dive into CO₂ tolerance and how it affects your nervous system, energy, and cardiovascular health.
Flip the Stress Switch — Reset Your Vagus Nerve — practical tools for activating the parasympathetic nervous system and lowering your baseline stress response.
Functional Breathing — How to Take Your Breath Back — understanding dysfunctional breathing patterns and how to correct them for lasting health benefits.
Shift Your State – Change Your Brain — how to change your state in any situation understanding and using heart-brain coherence.
Follow us on Instagram for a daily reminder to take a conscious breath. One mindful breath a day is where it starts.
Frequently Asked Questions About Breathing and Blood Pressure
How quickly can breathing affect blood pressure?
The effect of slow nasal breathing on blood pressure can be measurable within minutes — the parasympathetic nervous system responds rapidly to changes in breathing pattern. For sustained reduction in resting blood pressure, consistent practice over several weeks is what creates lasting change. Several studies have shown meaningful reductions in blood pressure after four to eight weeks of regular slow breathing practice.
Can breathing exercises replace blood pressure medication?
That is a question for your doctor, not for us. What the research shows is that slow nasal breathing works on the same physiological mechanisms that many blood pressure medications target — vasodilation, nervous system regulation, and heart rate control — but through a natural pathway. Many people find that a consistent breathing practice complements their medical treatment. Never stop or reduce medication without speaking to your doctor first.
How much time do I need to commit to see results?
Even five to ten minutes of slow, nasal breathing daily is enough to begin creating a measurable shift. The key is consistency rather than duration. Daily practice, even brief, trains the nervous system over time. If you can build a morning or evening routine around it, the habit forms quickly and the benefits accumulate.
Is nasal breathing difficult if I have chronic congestion?
Chronic nasal congestion is often itself a result of habitual mouth breathing — the nasal passages become less active and the mucus membranes less healthy when they are bypassed regularly. Switching to nasal breathing, even partially, tends to improve congestion over time as the passages are used more and the mucus membranes become better at their draining and filtering work. Start gently, and if congestion is severe, speak with a healthcare provider before attempting mouth taping or extended nasal breathing practice.
Does exercise breathing matter for blood pressure?
Yes. Breathing through the nose during exercise, even at moderate intensity, has been shown to reduce exercise-induced blood pressure spikes compared to mouth breathing. It also supports more efficient oxygen delivery through the nitric oxide and CO₂ mechanisms described in this article. For many people, nasal breathing during exercise feels uncomfortable at first — the pace simply needs to be slowed until the nasal passages can keep up. This adaption typically takes two to four weeks.
References
- Nose Breathing Lowers Blood Pressure, May Help Reduce Risk Factors for Heart Disease — Nasal breathing leads to lower blood pressure and reduced cardiovascular risk factors.
- Daily Breath Training Can Work as Well as Medicine to Reduce High Blood Pressure — Outlines the advantages of nasal breathing, including nitric oxide production and its effect on blood pressure.
- Metabolic Mechanisms of Vasodilation — Explores metabolic factors contributing to vasodilation, including the role of CO₂ in relaxing vascular smooth muscle.
- Effect of Carbon Dioxide on Pulmonary Vascular Tone — Research on how CO₂ influences pulmonary vascular tone and overall blood pressure.
- Breathing Exercises to Lower Your Blood Pressure — Harvard Health on how nasal breathing activates the parasympathetic nervous system and reduces heart rate and blood pressure.
About the author
Siv Jøssang Shields holds a Doctor of Chiropractic, a Master of Science in Physiology, and a Bachelor of Biology. She has been a practising chiropractor since 1996 and is a certified Master Breathwork Facilitator, Trauma-Sensitive HeartMath Practitioner, Soma Breath Instructor, and Certified Hypnotherapist. She has been teaching Neurogenic Tremoring since 2009, training directly under Dr. David Berceli, the founder of TRE. Together with Dr. Berceli and Alex Green, she co-created Neurogenic Integration — the world’s first fully online, self-paced TRE provider certification program. Siv is the co-founder of The Integrated Human, based in Voss, Norway, where she works with individuals and groups internationally through workshops, retreats, and certification programs.
