We have all had situations when one of our nostrils is blocked and we want the functionality of both nostrils to be restored as soon as possible.
However, in everyday life we do not notice the fact that 75% of the time we breathe with one nostril and 25% with the other. So one nostril is more dominant.
The role of the dominant nostril changes during the day and this is called the nasal cycle.
Although we usually do not notice it, during the nasal cycle one nostril becomes clogged and thus contributes less to the flow of air, while the other relaxes at the same time.
People notice the nasal cycle only if the blockage of one nostril is extremely pronounced and obvious, which happens in people who have a septal deviation.
While it may be logical to conclude that this also happens when people have a cold, scientists say that breathing difficulties and blowing through the nose during a cold have nothing to do with the nasal cycle. On the contrary, when we have a cold, it will be harder for us to breathe through both nostrils, no matter what stage of the nasal cycle we are in.