The nose is a normal respiratory organ that warms, humidifies the air we inhale and filters out foreign substances, allergens, and microorganisms. In this way, the oxygen in the air that reaches the lungs is transferred to the blood much more efficiently after being warmed and humidified.
Additionally, the resistance created against the airflow within the nose during breathing contributes to better expansion of the lower respiratory tract and lungs (naso-pulmonary reflex).
The most important role in performing these functions of the nose is carried out by the inferior turbinates (inferior conchae). The inferior turbinates, rich in blood vessels within their submucosal tissues, adjust the degree of warming, humidifying, and filtering of inhaled air according to the environmental conditions, as well as the resistance to airflow. Nasal obstruction caused by the hypertrophy of these inferior turbinates (concha hypertrophy), which critically perform these functions in a highly sensitive balance, is the most frequently observed cause of nasal blockage.
Due to the critical roles in normal bodily functions of nasal respiration, especially interventions targeting the inferior turbinates must be performed with great caution. These structures should be reduced in size in a manner that preserves their normal function and should never be completely removed except in very special circumstances.
If mouth breathing occurs due to nasal obstruction, the oxygen in the inhaled air is not adequately retained in the lungs, leading to a decrease in blood oxygen levels. The reduction in blood oxygen saturation, detected by sensors in the brain and the blood vessels supplying the brain, can trigger reflexes that over time may result in increased blood pressure (hypertension), heart rhythm problems, or heart failure.
Nasal obstructions also significantly degrade the quality of life by causing frequent throat infections, dryness in the throat, sleep disturbances, snoring, and sleep apnea as a result of mouth breathing.
The most common causes of nasal obstruction in adults are:
- Deviation of the septum, the cartilage and bone structure between the two nasal passages (septum deviasyonu),
- Problems in the nasal valve area located near the nasal bridge (nasal valve insufficiency),
- Enlargement of the nasal turbinates (concha hypertrophy).
- Nasal deviations can result from trauma, fractures of the nasal bone, birth trauma, unnoticed injuries during development, or genetic factors affecting the growth centers of cartilage and bone in the septum, leading to abnormal septum development as the nose grows with age.
- Nasal valve insufficiency occurs in two forms:
- Internal (intrinsic) insufficiency: narrowing of the airway passage due to septal deviation.
- External (extrinsic) insufficiency: structural weakening or inward curvature of the nasal valve region due to cartilage support loss or reduction during aesthetic surgeries, insufficient to withstand airflow resistance.
Nasal valve insufficiencies can be objectively identified not only through nasal examinations but also by acoustic rhinometry tests, which calculate the cross-sectional areas of different regions within the nasal passage. In patients with septal deviation, the majority often exhibit hypertrophy in the turbinates on the opposite side. This is due to reflexes developed to maintain normal functions by creating resistance to airflow and ensuring turbulence within the nose, leading to compensatory hypertrophy of the inferior turbinates.
Swelling of the nasal mucosa due to allergic reactions is another common cause of nasal obstruction. Patients with allergic rhinitis experience not only nasal blockage but also itching in the nose, sneezing, and clear, watery nasal and postnasal discharge.
Nasal and sinus infections, excessive reactions of nasal blood vessels to external stimuli (vasomotor rhinitis), polyps originating from the sinuses, turbinate hypertrophy (concha bullosa), and benign or malignant tumors within the nasal cavity can also cause obstruction.
In children, the most common cause of nasal obstruction is adenoid hypertrophy, especially in cases where obstruction begins after the age of two. Congenital obstructions may result from incomplete formation of the nasal canal or blockage at the posterior end of the nasal passage leading to the nasopharynx (choanal atresia). Additionally, allergies, sinusitis, and the insertion of foreign objects into the nose can cause nasal obstruction in children.
At night, nasal obstructions while lying down are caused by the accumulation of blood within the inferior turbinates. When standing, gravity assists the return of blood to the heart, allowing blood to drain from the inferior turbinates and causing them to shrink. However, when lying down, the reduced height difference between the heart and the head decreases gravitational support, making it harder for blood to return to the heart and causing blood to accumulate and swell the inferior turbinates.
In patients diagnosed with infections either through physical examination or radiologically, the primary approach should be to treat the infection with appropriate medications.
In patients diagnosed with allergies, administering suitable anti-allergic treatments can also reduce the symptoms of nasal obstruction.
In cases of chronic sinusitis and nasal polyps, appropriate surgical methods should be employed to remove polyps, open sinus drainage pathways, and ensure proper ventilation.
Nasal decongestant pills and sprays (such as Illiadin, Otrivin) are used early on and for short periods in the treatment of upper respiratory infections and allergic reactions. These medications constrict the blood vessels in the nasal mucosa, reducing the size of the turbinates and opening the nasal passages. Oral decongestants work similarly by constricting blood vessels. While decongestant drops and sprays provide significant relief very quickly, their prolonged use beyond 5-7 days can lead to rebound vasodilation and permanent changes in the nasal mucosa’s surface anatomy, hence they should be used with caution. Oral decongestants, on the other hand, can cause side effects such as palpitations, sleep disturbances, and restlessness in children, and are contraindicated in individuals with heart rhythm disorders, high blood pressure, and prostate enlargement as they can exacerbate these conditions.
The decongestant test is the easiest method to understand the role of inferior turbinates in nasal obstruction. If significant nasal passage opening occurs within 5-10 minutes after applying a nasal decongestant spray, it indicates that the obstruction is caused by the inferior turbinates.
Even after this application, if the relaxation in one passage is significantly less than the other, it should raise suspicion of septal deviations or other pathologies. Acoustic rhinometry assessments performed before and after the decongestant test will quantitatively demonstrate the role of the inferior turbinates, particularly their anterior parts, in nasal obstruction.
In patients who do not have allergies or infections, or whose nasal obstruction symptoms persist despite medical treatment, surgical treatment options become relevant.