Today I found out around 85% of humans only breathe out of one nostril at a time. Even more interesting is that the pattern of switching from breathing out of one nostril to the other happens in a cyclical fashion, with about four hours or so between each switch typically; although, this can vary from person to person and vary based on your body position or nasal congestion.

The first known instance of someone studying this “nasal cycle” was German nose specialist, Richard Kayser in 1895. How your nose accomplishes this switch is via erectile tissue in your nose, which is very similar to the erectile tissue in a penis or clitoris. Erectile tissue will swell up in one nostril, mostly blocking it, and at the same time erectile tissue in the other nostril will shrink, opening it up for breathing.

Even more interesting is that depending on which nostril you are predominately breathing out of at any given moment, it seems to greatly affect your body and brain.

For instance, a study in 1988 showed that breathing through your right nostril significantly increases blood glucose levels, while breathing through your left nostril has the opposite effect. It is speculated from this that abnormal nasal cycles, such as breathing through your right nostril for many years without a switch, may be one contributing factor in certain cases of diabetes.

Another study in 1993 showed that when you are breathing through your right nostril, you will use significantly more oxygen than when breathing through your left.

Most interestingly of all, yet another study published in 1994, showed that when you are breathing through your left nostril, the right hemisphere of your brain will be more active or dominant and vice-verse when you are breathing through your right nostril.

Even though this switching happens naturally in a cyclical fashion, you can affect it in more ways than just plugging one nostril or the other to force breathing through the one you want. If you lay down on one side or the other, after around 12-15 minutes, the erectile tissue in the nostril on that side will begin to swell up and the other side will decrease its swelling so that if you are lying on your left side, then your right nostril will open up and your left nostril will close up.

It is thought that this nasal cycle could be the reason that when you sleep on your side, you will often switch sides throughout the night at very regular intervals, even if you weren’t in the slightest bit uncomfortable. It could just be that your body needs to switch which nostril it is breathing out of, so you feel the urge to roll over to your other side while you sleep.

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Bonus Facts:

Research has shown that the nasal cycle gets weaker as you get older.

The nasal cycle is thought to be regulated by the autonomic nervous system via the sympathetic nervous system.

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