top of page

Our Nose is the Gateway to Our Immune System

Updated: Apr 11, 2020

During this COVID-19 pandemic, standard recommendations have been given to help lower one’s risk of catching the virus, such as frequent hand washing, using masks, social distancing, etc. Aside from this list, there is 1 major factor that can have a huge impact on our health, and that is our mode of breathing.

Physiologically, humans have the ability to breathe through the mouth or the nose. However, there are significant differences in how each of these modes of breathing influence our bodies and our health.

Breathing through the nose is the first line of defense against airborne disease. During nasal breathing, the nose warms, moistens, and filters the air that enters the body and protects us from viruses. The paranasal sinuses in the nasal cavity also produce Nitric Oxide, which is a powerful anti-bacterial, anti-viral, and anti-inflammatory agent, and can only be accessed through nasal breathing.

Mouth breathing does not offer any of the above-mentioned benefits. In fact, mouth breathing allows the bacteria in the air to directly enter the body, increasing the risk of contracting illnesses. Additionally, mouth breathing causes the breath to remain shallow in the upper chest instead of filling deep into the diaphragm. This shallow, upper chest breathing activates the sympathetic nervous system (aka “fight or flight”), which causes the body to release increased levels of cortisol, the primary stress hormone. High levels of cortisol lead to feelings of anxiety and stress and actually suppress the immune system.

Addressing poor breathing habits helps to bring the body into relaxation mode by activating the parasympathetic nervous system (aka "rest and digest"). Re-training the body to breathe nasally, using slow, light, diaphragmatic breathing, is significant in reducing stress and anxiety and strengthening the immune system.


Akerstrom, S., M. Mousavi-Jazi, J. Klingstrom, M. Leijon, A. Lundkvist, and A. Mirazimi. 2005. Nitric oxide inhibits the replication cycle of severe acute respiratory syndrome coronavirus. J. Virol. 79:1966-1969.

Blond, D., H. Raoul, R. Le Grand, and D. Dormont.2000. Nitric oxide synthesis enhances human immunodeficiency virus replication in primary human macrophages.J. Virol.74:8904-8912.

Coleman, J. W.2001. Nitric oxide in immunity and inflammation.Int. Immunopharmacol.1:1397-1406.

Courtney, R., Functions and dysfunctions of breathing and their relationship to breathing therapy.International Journal of Osteopathic Medicine, 2009. 12: p. 78-85.

Ooi EH, Wormald P-J, Tan LW. Innate immunity in the paranasal sinuses: a review of nasal host defenses. American journal of rhinology 2008; 22:13-19.

Pereira VH, Campos I, Sousa N. The role of autonomic nervous system in susceptibility and resilience to stress. Current Opinion in Behavioral Sciences 2017; 14:102-107.

bottom of page