In daily life, patients with sinusitis, allergic rhinitis, and other conditions are often advised to rinse their sinuses to relieve symptoms, such as clearing nasal secretions, reducing mucosal swelling, and improving airway function. However, many people experience pain in their nasal or sinus area when trying to rinse, and may even abandon this effective treatment. So, what exactly causes sinus irrigation pain?
Physiological Structure
Anatomical Characteristics of the Sinuses
The sinuses are air-filled cavities located within the skull surrounding the nasal cavity. They include the maxillary, ethmoid, frontal, and sphenoid sinuses. They connect to the nasal cavity through small openings (ostiae), forming a "duct-cavity" system. This structure forces irrigation fluid to enter the sinuses through narrow ostiae. If the ostiae are narrowed due to inflammation or swelling, the flow of irrigation fluid is blocked, resulting in localized high pressure, irritation of the sinus mucosa, and pain. For example, the maxillary sinus opening is located in the middle meatus of the lateral nasal wall, a discreet location with a diameter of only 2-3 mm. This makes it easy for concentrated pressure to cause pain during irrigation.
Sensitive Innervation of the Mucosa
The sinus mucosa is richly covered with trigeminal nerve endings, which are extremely sensitive to mechanical stimuli (such as pressure changes), chemical stimuli (such as abnormal saline concentrations), and thermal stimuli (such as excessively cold or hot irrigating solutions). When irrigating solutions directly impact the mucosa or sinus opening, these nerve endings are activated, transmitting pain signals to the brain. Studies have shown that the pain threshold of the sinus mucosa is much lower than that of the skin, which is one reason why irrigating can be more painful.
How to Use
Improper Irrigating Solution Temperature and Concentration
Temperature: The human nasal mucosa is temperature-sensitive, and the optimal irrigating solution temperature is 32-38°C (close to body temperature). Water temperatures that are too low (e.g., below 25°C) can cause vasoconstriction in the mucosa, leading to local ischemic pain. Water temperatures that are too high (e.g., above 40°C) can burn the mucosa and worsen inflammation. Concentration: Normal saline (0.9% sodium chloride solution) is the standard solution for sinus irrigation. If the concentration is too high (e.g., over 2%), the increased osmotic pressure can lead to dehydration of mucosal cells, causing stinging. If the concentration is too low (e.g., below 0.5%), insufficient osmotic pressure may prevent effective secretion removal and may even increase sinus pressure due to fluid retention.
Irrigation Posture and Pressure Control
Posture: Correct irrigation posture requires tilting the head forward, keeping the mouth slightly open, and avoiding swallowing. If the head is tilted back or at an incorrect angle, the irrigant may enter the Eustachian tube (the tube connecting the nasal cavity to the middle ear), causing pressure changes in the middle ear and leading to ear pain or dizziness.
Pressure: Control the water pressure during irrigation and avoid excessive pressure. High-pressure irrigation (e.g., direct injection with a syringe) may force open narrow sinus ostia and damage the mucosa. Low pressure, on the other hand, may not effectively remove secretions. It is recommended to use a dedicated nasal irrigator that controls the flow rate through gravity or gentle pressure.
Individual Differences
Severity of Sinusitis
In acute sinusitis, congestion and swelling of the sinus mucosa can lead to narrowing or even obstruction of the sinus ostia. This makes it difficult to drain fluid during irrigation, leading to accumulation of high pressure within the sinuses and irritation of pain nerves. In patients with chronic sinusitis, nasal polyps or anatomical variations (such as a deviated septum) can further obstruct the sinus ostia, making irrigation more difficult and increasing the risk of pain. For example, one clinical study found that patients with nasal polyps experienced 2.3 times more pain during irrigation than the general population.
Allergies and Mucosal Hyperreactivity
In patients with allergic rhinitis, the nasal mucosa is highly sensitive to tiny impurities in the irrigation solution (such as partially dissolved salt particles) or temperature fluctuations. Furthermore, these patients often have hypertrophic turbinates, which can cause fluid to accumulate in the nasal cavity during irrigation, prolonging its contact with the mucosa and exacerbating irritation.
Psychological Factors
Psychological state can significantly influence pain perception. Patients undergoing sinus irrigation for the first time may experience anxiety due to unfamiliarity with the procedure or fear of choking. This anticipatory anxiety can lower the pain threshold, causing even mild stimulation to be perceived as painful. Furthermore, negative experiences (such as previous pain caused by improper procedure) can form conditioned reflexes, further exacerbating pain during subsequent irrigations.
Pain during sinus irrigation is not inevitable. Comfort can be significantly improved by adjusting the technique, choosing an appropriate irrigation solution, managing medical conditions, and engaging in psychological adjustments. For example, using premixed saline to avoid concentration errors, using a pulsed irrigator to reduce pressure shock, or using a nasal decongestant (such as oxymetazoline) before irrigation to temporarily reduce swollen mucosa can all effectively reduce the risk of pain. If pain persists or worsens, seek medical attention promptly to investigate for anatomical abnormalities or serious infection.
