In each side of the nose, there is an internal and external nasal valve located in the middle and lower parts of the nose. The nasal valves are the narrowest part of the nasal airway and they work to limit airflow. When you breathe, your nose is where more than half of your airflow resistance occurs.
The anterior portion of the nose, including the internal and external nasal valves, is where most of the airflow resistance occurs, but it is the internal nasal valve where most of the flow resistance is created.
Resistance in the nose is important, as the nose processes the air that you breathe before it enters your lungs–it helps to warm, humidify, and purify the air you breathe to protect your health. This airflow resistance is important for good pulmonary function.
When patients have problems with nasal airflow, it is usually because the internal nasal valve has become more narrow restricting air from passing freely into the nose. This narrowing may occur when the turbinate swells or the nasal sidewall collapses during inspiration. Consequently, this nasal valve collapse makes it difficult for patients to breathe through their nose (nasal obstruction), causing nasal congestion and blockage.
During your consultation, the ENT (ear, nose, and throat) doctor will ask you to inhale through your nose to see if the nasal sidewall moves inward and collapses leading to blockage of nasal airflow. Your doctor will also do a visual exam of your nasal cavity using a 4mm, lighted endoscope, evaluating the condition of your nasal valves as well as all adjacent structures. This is done not only to rule out all possible causes of your nasal obstruction (such as a deviated septum, enlarged turbinates, sinus masses, polyps, and enlarged adenoids), but also for proper diagnosis and treatment recommendation.
Another test your doctor may perform is the Cottle test, which is done to evaluate nasal valve stenosis (narrowing of a passage). With this test, the cheek of the evaluated side is gently pulled laterally with 1 or 2 fingers as you inhale, which opens the valve. If your breathing is better when this is done, then it implies that a collapse of the valve is present on that side. If breathing is not better, then that means there is another cause of the obstruction elsewhere in the nose.
If septal surgery alone doesn’t correct nasal obstructive impairment, then nasal valve surgery should be considered. A straight septum is important for unimpaired nasal valve function. This surgery helps to restore normal anatomy of the nasal valve and improve airflow without increasing either rigidity or collapsibility of the nasal valve.