This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Nasal cycle

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

Airflow through the nasal passages is normally asymmetrical because of alternating changes in nasal resistance in each nostril. The mechanism involves changes in sympathetic tone to the venous erectile tissue of the nasal mucosa; increased sympathetic vasoconstriction causing resistance to fall.

The total nasal resistance to airflow remains fairly constant as changes between the nasal passages tend to be reciprocal so that the patient is usually unaware of the phenomenon.

This nasal cycle has a periodicity of approximately 2 hours and is found in 80% of the population. The reason for its existence is uncertain. A simple explanation is that it permits one side of the nose to go through a rest period and recover from the minor trauma of conditioning the inspired air.

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page