The nasal cycle is a physiological phenomenon during which each side of the nose alternates through phases of congestion and decongestion. 1 This alternating turgescence of the inferior turbinates occurs in 80% of normal individuals. As blood fills in the turbinates in one fossa, blood is shunted away from the opposite turbinates, resulting in decongestion. 2 In the lateral decubitus position, the turbinates in the dependent nasal fossa fill with blood. 3 This alternating positional obstruction and the resulting asymmetric airflow is thought to have some benefit on overall factory sensitivity.
Hence, the nasal cycle is an alternation between the left and right sides of the nose and time. However, the total nasal resistance remains constant. In pathological conditions, the nasal cycle may influence asymmetric breathing due to underlying nasal obstruction. 4 The autonomic nervous…
