Here's a question to which I've not been able to get clear answer to date, after researching widely online, and also consulting multiple doctors and ENTs: Is it normal, when lying in a horizontal position, to always have one side of one's nose blocked off and not passing air, swapping sides on a time scale similar to the nasal cycle?
The nasal cycle is well-known but is not said to be related to lying in a horizontal position. It is said to be distinct from pathological nasal congestion and obstruction.
In summary: What proportion of people experience total one-sided nasal obstruction when lying horizontal (majority of people, or otherwise)?