With A Deviated Septum, Why Does Nasal Obstruction Come and Go?

A deviated septum is a well known factor causing nasal obstruction in people. However, many patients with a deviated septum will also state that there are times when they can breath just fine from their nose. As such, can a deviated septum truly be the cause of their nasal obstructive symptoms? Shouldn't the obstruction be constant?

The blunt answer is ABSOLUTELY nasal obstruction can be intermittent OR constant with a deviated septum!!! It's more a question of degree.

To begin with, a deviated septum is when the wall that separates the right and left nasal cavities is bent one way (green arrow) instead of being perfectly straight.

If there is no mucosal swelling, a person with a deviated septum is able to breath from both sides just fine. However, if there is the slightest bit of mucosal swelling from turbinate hypertrophy, allergies, upper respiratory infection, or any other environmental irritation, the side that is more narrow will obstruct much more readily with less swelling given there is just "less room" for swelling to occur before obstruction occurs.

Below is the same exact nose and septum as above, but with mucosal swelling present.

As you can see, with the same exact amount of swelling present, the deviated septum significantly influences how much space is present for air to pass through compared with a straight septum.

As such, even though a deviated septum may not technically be obstructive, given there is less room for any swelling to be accomodated, a patient will complain of nasal congestion and obstruction much more readily compared to someone with a straight septum due to the slightest changes in mucosal swelling.

How is a deviated septum fixed? Click here to read more.

Of course, one can try and control the mucosal swelling to avoid any surgical intervention, typically with steroid or anti-histamine nasal sprays. The downside is that such medications need to be used daily to prevent swelling from occurring in the first place.

Nasal Congestion Affected By How Well the Nose is Able to Cool Itself

Researchers at Monell Chemical Senses Center have figured out that nasal congestion is influenced by more than just nasal airflow. Apparently temperature and humidity influence the perception of nasal congestion just as much as how physically obstructed the nose is.

By having volunteers breath air with variations in temperature and humidity, they have determined that cool and dry air minimizes nasal congestion without any change in how open the nasal cavity is.

By taking into account other measured variables, they have deduced that nasal congestion is influenced by how well the nose is able to cool itself from the nasal airflow specifically. The more warm and humid the air is, the less able the nose is able to cool itself leading to perception of nasal congestion.

With actual nasal obstruction, it may be not so much that you can't breath that causes the feeling of nasal congestion, but rather the reduced ability of the nose to cool itself from the absence/reduction of air circulation within the nasal cavity.

So... if nasal cooling influences perception of nasal congestion, this may be one of many factors that may help explain the phenomenon of Empty Nose Syndrome. Patients suffering from Empty Nose Syndrome have an abnormally open nasal cavity from extensive surgical removal of internal nasal structures... yet complain the most bitterly about how congested their nose feels.

This information may also help guide treatment in patients with tracheostomy who also have a totally open nose, but because they breath thru an opening in the neck, have no nasal airflow in the nose which leads to the sense of nasal congestion.

Based on this new research, in these particular patient populations, providing allergy medications like steroid nasal sprays and anti-histamines may not be the best way of addressing nasal congestion.

Clearly, more research is needed on this topic, but certainly opens other new avenues of possible treatment protocols.


Reference:
Perceiving Nasal Patency through Mucosal Cooling Rather than Air Temperature or Nasal Resistance. PLoS ONE 6(10): e24618. doi:10.1371/journal.pone.0024618