You turn off the light, sit on your right side, and the nostril on the same side suddenly seems less able to pass air. You turn around, and it’s the other side that looks embarrassed. This feeling can be confusing, especially when it returns during sleep.
Most often, it is explained by a normal phenomenon:
the nasal cycle. But an obstruction that wakes you up, forces you to breathe through your mouth or always stays on the same side deserves to be taken seriously.
Why don’t both nostrils breathe the same?
Our two nostrils do not always function perfectly symmetrically. Inside the nose, the nasal turbinates contain tissue rich in blood vessels. They can inflate then deflate alternately, which changes the passage of air from one side then the other.
This is what we call the nasal cycle. At times, one nostril lets more air in while the other seems more “closed.” Then the balance reverses. Most of the time, we don’t notice it. But in the evening, lying down in silence, a variation that is usually discreet can become very noticeable.
Work published in PLOS One measured and characterized the variations in nasal airflow and the dominance of one nostril over the other. The study also looked at posture and a phenomenon partly linked to the autonomic nervous system. Its scope remains physiological: it helps to understand the mechanism, but it does not, on its own, explain all the nocturnal discomforts or suggest a treatment.
Why does the side position increase discomfort?
Position can change sensation. According to this study, lateral posture is associated with greater air flow in the contralateral nostril, that is to say the nostril located on the side opposite to that on which one is lying. In other words, when you sleep on one side, the nostril above can let air pass through betterwhile the one below appears more cluttered.
This mechanism does not mean that the nose is “diseased”. It can simply make an already present alternation more visible. On the other hand, if the discomfort is significant, the nasal cycle should not serve as an automatic explanation. A cold, inflammation of the nose, an allergy or an abnormality of the nasal septum can also occur.
When discomfort occurs in the context of nasopharyngitis, it is often temporary. Health Insurance recommends in particular, in this context, cleaning the nose with physiological serum. Before bed, this gesture can improve comfort, especially if the nose is congested. Ventilating the room, avoiding tobacco smoke and not overheating the room are also useful guidelines for limiting irritation of the respiratory tract.
When should we look for another cause?
The warning signal is not the fact of feeling an alternation between the nostrils. What should trigger a reaction is repetition or intensity: a blocked nose that comes back every night, which prevents you from sleeping, which is accompanied by fatigue when you wake up or which forces you to breathe through your mouth for a long time.
An allergy can, for example, cause chronic obstruction, sometimes associated with sneezing, itching or clear discharge. Nasopharyngitis may cause more transient obstruction, with other symptoms of viral upper respiratory infection. And if the discomfort is mainly on one side, another avenue can be considered.
Health Insurance indicates that a frequent or permanent feeling of a blocked nose, often on one side only, can suggest a
deviation of the nasal septumand that an ENT assessment is necessary to make the diagnosis. This point is important: only an examination can distinguish an anatomical feature from an obstruction linked to inflammation or infection.
“Medical or ENT advice is indicated if the obstruction remains
always on the same sidepersists during the day, is accompanied by epistaxis, facial pain, decreased sense of smell, purulent discharge, or severe snoring with pauses in breathing; chronic nasal obstruction may result from rhinitis, septal deviation, turbinal hypertrophy or, more rarely, polyposis” confirms Dr. Gérald Kierzek, emergency physician and medical director of True Medical.
You must also be careful with vasoconstrictor decongestant sprays. These medications should not become an evening ritual. They should not be used for more than five days in a row. Nasal forms, when indicated, require a medical prescription. Excessive use exposes you to undesirable effects and sometimes maintains the use of the product.
If you need a decongestant to help you sleep, or if the discomfort returns as soon as you stop it, ask your doctor or pharmacist for advice. A nose that alternates from one nostril to the other may simply follow its natural rhythm; sleep regularly disrupted by obstruction deserves a real explanation.