Benefits of nasal breathing in comparison to mouth breathing

Nasal breathing is generally preferable to mouth breathing when you’re at rest: it conditions and filters incoming air, and may support respiratory health, blood flow, facial and dental development, and memory. 1 2

• Nasal resistance and air conditioning: The extra resistance of nasal breathing can help inflate the lungs more, while the nasal passages warm and moisten inhaled air—conditions described as more favorable for lung health. 3
• Nitric oxide and blood flow: The nasal passages produce nitric oxide, which can relax smooth muscle around blood vessels and promote vasodilation, potentially supporting blood flow and delivery of nutrients to tissues. 4
• Respiratory defenses: The nose filters pathogens, and its hairs, mucus, and microbiome help protect against incoming infections. Mouth breathing is associated with more upper respiratory infections; nasal breathing also warms incoming air in ways that may make it harder for cold and flu viruses to establish infection. 5 6
• Dental health and facial structure: Habitual mouth breathing is associated with changes in jaw and facial structure, while switching to nasal breathing is described as supporting improvements in teeth and jaw structure, including cheekbone and jaw positioning. 7
• Memory recall: In a study discussed on the episode, memory and recall were better when people learned information while breathing through the nose rather than the mouth. One proposed explanation is that nasal breathing provides stronger respiratory signals through the olfactory system to the brain. 8