General Medical Information

Nasal Cycle

Thomas V. Mccaffrey

The nasal cycle is the observed intrinsic variability of the nasal airway resistance that occurs in a cyclic pattern in as many as 40% of persons. This cyclic engorgement and decongestion of the cavernous tissue of the nose have been known since the beginning of the nineteenth century. The cycle has a duration of 2 to 6 hours. During the cycle, one side of the nose congests while the opposite side decongests. This means that total nasal resistance remains essentially constant despite the localized alternating congestion of each side of the nose.