The nasal valve is the narrowest segment of the nasal airway and acts as the primary regulator of air moving into the lungs. This area creates the greatest resistance to airflow, which is essential for healthy respiration. Its function governs how comfortably you breathe and how effectively the nose conditions the air. Maintaining the valve’s integrity is important for a clear path for inspiration.
Anatomy and Components
The nasal valve consists of two distinct areas: the internal and external nasal valves.
The Internal Nasal Valve (INV) is the narrowest point, located about 1.5 centimeters inside the nostril. This region is formed where the caudal edge of the upper lateral cartilage meets the nasal septum, with the head of the inferior turbinate forming the floor. Typically, the angle between the septum and the upper lateral cartilage measures between 10 and 20 degrees.
The External Nasal Valve (ENV) is located closer to the entrance, defining the nostril itself. Its boundaries include the flexible soft tissues of the ala (nostril rim) laterally and the columella (tissue separating the nostrils) medially. Both valves rely on the stability of cartilage, soft tissue, and muscle to maintain their shape.
Crucial Role in Airflow
The narrow configuration of the nasal valve regulates the speed and pressure of inspired air. By constricting the airway, the valve creates a high-resistance zone necessary for air conditioning. This allows the air to be warmed, humidified, and filtered before it travels deeper into the respiratory system.
This physiological mechanism involves principles of fluid dynamics, including the Bernoulli principle. The valve converts the initial airflow into a more turbulent pattern, which enhances the exchange of heat and moisture with the nasal mucosa. This mechanism ensures maximum contact with the mucosal lining for proper conditioning and supports efficient gas exchange in the lungs.
When the Valve Fails
When the supporting structures weaken, the result is Nasal Valve Collapse (NVC) or obstruction. This occurs when the lateral wall of the nose, particularly the INV, is pulled inward during the negative pressure of inspiration. This structural compromise significantly narrows the airway and causes a feeling of nasal blockage.
Causes of Nasal Valve Collapse
Failure is often caused by factors that compromise the strength of the nasal cartilage. Common causes include physical trauma to the nose or previous nasal surgery. The natural aging process can also lead to NVC, as cartilages lose their rigidity and elasticity over time. Other structural issues, such as a deviated septum or scar tissue from chronic inflammation, can contribute to the narrowing.
Symptoms
Patients typically experience difficulty breathing inward through one or both sides of the nose. This obstruction often worsens during physical exertion when breathing is heavier and internal negative pressure is greater. Symptoms are also exacerbated when lying down, which can lead to chronic mouth breathing, snoring, and poor sleep quality.