About 85% of people breathe through only one nostril at a time. What's even more interesting is that the pattern of switching from breathing through one nostril to breathing through the other happens in a cyclic fashion, usually with about four hours or so between each switch; however, this can vary from person to person and based on where your body is It may vary depending on the condition of nasal congestion.
The first person to study this "nasal circulation" was German nose expert Richard Kayser in 1895. How the nose accomplishes this conversion is through the erectile tissue in the nose, which is very similar to the erectile tissue in the penis or clitoris. The erectile tissue in one nostril will swell, mostly blocking it, while the erectile tissue in the other nostril will shrink, opening it up for breathing.
What's even more interesting is that depending on which nostril you're primarily breathing through at any given moment, it seems to greatly affect your body and brain.
For example, a 1988 study showed that breathing through the right nostril significantly increased blood sugar levels, while breathing through the left nostril had the opposite effect. It is speculated that abnormal nasal circulation, such as breathing through the right nostril for many years without switching, may be a contributing factor in some cases of diabetes.
Another study from 1993 showed that when you breathe through your right nostril, you use more oxygen than when you breathe through your left nostril.
Most interestingly, another study published in 1994 showed that the right hemisphere of your brain is more active or dominant when you breathe through your left nostril, and vice versa when you breathe through your right nostril .
Although this switching occurs naturally in a cyclical manner, you can influence it in many ways beyond just plugging one nostril or the other to force breathing through your desired nostril. If you lie on one side or the other, after about 12-15 minutes the erectile tissue in your nostril will start to swell and the swelling on the other side will decrease, so if you lie on your left side, then your The right nostril will open and the left nostril will close.
It's thought that this type of nasal circulation may be caused by the fact that when you sleep on your side, you often switch sides at very regular intervals throughout the night, even though you're not feeling the slightest discomfort. It could just be that your body needs to switch which nostril you're breathing out of, so you feel the urge to flip to the other side while sleeping.
