Saline solution, a commonly used nasal irrigation solution, is widely used to relieve symptoms of rhinitis and sinusitis because its composition is similar to the osmotic pressure of human body fluids. However, the debate about whether saline solution causes nasal dryness persists.
The Scientific Principles of Saline Nasal Irrigation
The osmotic pressure of saline solution (0.9% sodium chloride solution) is consistent with that of human extracellular fluid. Its core mechanisms of action include:
Osmotic Pressure Balance: Saline solution maintains the water balance inside and outside nasal mucosal cells through its isotonic properties, preventing cell dehydration or swelling caused by hypertonic or hypotonic solutions.
Mucosal Protection: During irrigation, saline solution can remove allergens, pathogens, and inflammatory secretions from the nasal cavity, reducing mucosal irritation while retaining natural moisturizing components in the mucus layer (such as mucin).
Humidity Regulation: After rinsing with saline solution, a thin film of moisture forms in the nasal cavity. This film gradually evaporates during respiration but does not excessively remove moisture from the deeper layers of the mucosa.
Clinical Evidence: Multiple studies have shown that proper use of saline nasal irrigation can improve nasal dryness symptoms. For example, a 2025 controlled trial in patients with allergic rhinitis showed that patients in the twice-daily saline irrigation group had significantly higher nasal moisture scores than the non-irrigation group, and no dryness-related discomfort was reported.
What situations might trigger dryness?
Although saline itself is safe, the following factors may lead to nasal dryness:
Uncontrolled Concentration and Temperature
Misuse of Hypertonic Saline:If the saline concentration exceeds 0.9% (e.g., 1.5%-2.3% hypertonic saline), long-term use can damage the mucosal barrier, leading to cell dehydration. For example, a patient who mistakenly used hypertonic saline to irrigate their nasal cavity developed mucosal erosion and nasal bleeding a week later.
Improper Water Temperature: Cold water (below 25℃) can stimulate vasoconstriction in the nasal mucosa, reducing local blood supply; excessively hot liquids (above 40℃) may directly scald the mucosa. It is recommended to control the irrigation water temperature at 35-37℃, close to body temperature.
Incorrect Operation Method
Excessive Irrigation Pressure: Using a syringe or squeeze bottle with excessive force may wash away the moisturizing components in the mucus layer, leading to mucosal exposure. Correct operation should use a gentle, slow irrigation method, avoiding direct impact on the nasal septum.
Excessive Irrigation Frequency: Frequent irrigation more than 3 times daily may dilute the mucus, weakening its moisturizing function. Clinical recommendation is 1-2 times daily, with an appropriate increase during acute flare-ups.
Individual Differences and Underlying Diseases
Patients with Dry Rhinitis: These patients have insufficient secretory function in their nasal mucosa. After saline irrigation, a temporary feeling of dryness may occur due to the slow recovery of the mucus layer.
Drug Effects: Patients using antihistamines or nasal decongestants long-term already have dry nasal mucosa; additional saline irrigation may worsen discomfort.
How to Safely Use Saline Nasal Irrigation?
To minimize the risk of dryness, the following principles should be followed:
Choose compliant products
Prioritize using pre-prepared medical saline solution (such as 0.9% sodium chloride injection). Avoid self-preparing or using iodized table salt (iodine may irritate the mucous membranes).
Children or sensitive individuals can choose special nasal rinse solutions with added moisturizing ingredients such as sodium hyaluronate.
Follow standard operating procedures
Positioning: Tilt your head forward 30° and breathe through your mouth during rinsing to prevent saline from flowing into the Eustachian tubes and causing otitis media.
Instrument sterilization: Clean the nasal irrigator after each use and sterilize it by boiling regularly to prevent bacterial growth.
Post-rinsing care: After rinsing, apply a small amount of olive oil or a special nasal moisturizing cream to the nasal vestibule with a cotton swab to enhance mucosal hydration.
Combine with auxiliary measures
Environmental humidification: Use a humidifier during dry seasons to maintain indoor humidity at 40%-60%. Dietary adjustments: Increase fluid intake (1500-2000ml daily) and consume more fruits and vegetables rich in vitamins A and C (such as carrots and citrus fruits) to promote mucosal repair.
Saline solution itself does not cause nasal dryness; its safety has been extensively clinically verified. However, improper concentration control, incorrect application, or individual differences may cause temporary dryness. Users can minimize the risk by strictly following the prescribed usage instructions, combined with environmental adjustments and dietary care. For persistent dryness or bleeding, it is recommended to seek medical attention promptly to rule out underlying conditions (such as Sjögren's syndrome or deviated nasal septum), rather than blaming the saline solution itself.
