My current illness has acquainted me more intimately than I’d like to be with how my nose is functioning. Specifically, I’ve woken up every morning this week with the sensation that I could only breath out of one side of it. As I sought out information about why this was happening, I was delighted to learn about an entire aspect of biology I’d been overlooking, which is called the nasal cycle.
Tissue within our nose is able to be “erect” and to constrict on one side at a time. This means that one side is receiving more airflow than the other. Our general preference tends to mirror our handedness, so left-handed people breath more through the left-side and vice versa. I’m right-handed and the left side of my nose has been the one that’s felt closed every morning, so it tracks with this. (Note that the second study I found showed the opposite pattern).
Our autonomic nervous system, which I’ve previously discussed, is what is responsible for the shifts that occur every few hours in terms of which nostril is taking in more air. The side that we lay on affects this cycle. We switch less frequently when we are asleep than we do when we are awake. I’ve been waking up at odd times for the past several nights since I got sick, which makes me wonder if my brain is trying to change over the left side, realizing no air is coming in, and then alerting me so that I will adjust my position.
One theory as to why we have a nostril taking in a lot of air and another that is taking in less air is that we are able to notice different aspects of smells depending on how the air is flowing through our nose. I feel like I’m only picking up the “loud” notes of the few scents I can currently detect, which seems to fit with this idea. It is thought that perhaps we need these differences in scent detection to sniff out happy smells like tasty food as well as smells that portend danger such as wild animals.
The speed of our breathing also affects how our nose works. I’ve examined the benefits of slow breathing and can now add that it has an impact on our nasal cycle. Breathing more slowly is linked with having a greater difference between the left and the right nostril airflow. Shallow breathing tends to cause the airflow to be more balanced.
Before examining the research on this topic, I did not know that my nose was shifting every few hours in terms of which nostril received more air. It’s frustrating that it took a bout of a respiratory illness to lead me to slow down enough to consider how this part of my body works, but I think I will now have more appreciation for simple joys such as actually being able to smell the food I’m eating and being able to breath in deeply through my nose without feeling restricted. How is your nose functioning? Do you have any sense of breathing in through one side of it more than another? What’s the connection between the rate at which you breath and your enjoyment of pleasant smells?