Nasal Patency Tests: Bedside Assessment and Objective Measures
Nasal patency tests assess how freely air passes through each nasal passage. A blocked-nose sensation is important, but it does not always match measured airflow: mucosal swelling, the nasal cycle, septal shape, secretions and the patient’s perception can all influence symptoms. Bedside tests help compare the two sides and guide examination. They do not identify the cause by themselves.
Learning outcomes: Define nasal patency; perform and describe simple comparative bedside assessments; explain the role and limits of peak nasal inspiratory flow and specialist objective tests; recognise unsafe or unreliable testing; and document findings with an appropriate plan.
Clinical safety: These notes are for revision and supervised clinical learning. Use gentle, non-invasive methods first. Do not insert cotton, probes or instruments into the nose to test airflow. Follow local protocols and seek urgent assessment for respiratory distress, suspected nasal button battery, significant trauma, uncontrolled bleeding or a concerning unilateral mass.
What does nasal patency mean?
Nasal patency describes the openness of the nasal airway to inspiratory and expiratory flow. Airflow depends on the size and shape of the passage, mucosal congestion, secretions and the pressure generated during breathing. Each side may differ. The normal nasal cycle also causes alternating changes in congestion, so a small difference between nostrils at one moment does not automatically indicate disease.
Ask what the patient means by “blocked”: one or both sides, constant or intermittent, worse at night or with exercise, and associated with sneezing, itching, discharge, loss of smell, facial pain, bleeding, trauma or a foreign-body possibility. A history and examination give meaning to any test result.
When to assess patency
- To compare reported obstruction between the right and left nostrils.
- During a structured nasal examination when congestion, a deviated septum, a mass, secretions or turbinate enlargement is suspected.
- To monitor symptoms or response to a clinician-directed intervention, where a repeatable measure is available.
- In infants or children with noisy breathing or difficulty feeding, as part of a careful airway assessment by an appropriately trained clinician.
Do not let a simple test delay care: Stridor, cyanosis, marked work of breathing, inability to feed, rapidly worsening obstruction, major facial trauma or a suspected button battery requires urgent clinical assessment rather than repeated bedside airflow testing.
Preparation and equipment
Explain that the assessment compares airflow and should not hurt. Sit the patient upright in a comfortable position. Observe breathing at rest first, and allow recovery after walking or distress. Ask the patient to breathe through the nose with the mouth closed only if comfortable and safe.
A clean, smooth metal mirror or spatula may show condensation. A small wisp of cotton held outside the nostril can show movement. Use good light for inspection. Clean shared equipment between patients and do not touch the nostril with the testing surface.
Record whether the patient is resting, which nostril is tested, whether the other side is gently occluded, and whether the method is subjective or measured. Note recent exercise, crying, nasal sprays, decongestants or a respiratory infection if relevant.
Simple bedside tests
1. Observe breathing through each nostril
- Ask about the side that feels blocked before demonstrating a manoeuvre.
- Observe quiet breathing. If appropriate, ask the patient to close the mouth and breathe gently through the nose.
- Gently occlude one nostril externally and ask the patient to breathe through the other; then compare sides. Do not compress the nasal bridge or obstruct breathing for longer than the patient tolerates.
- Ask the patient to describe airflow and discomfort. Stop for dizziness, distress or breathlessness.
This is a subjective comparison. It can be affected by effort, anxiety, age, cooperation, the nasal cycle and the degree of occlusion. A patient may perceive obstruction even when airflow is present, or may have reduced airflow without describing it clearly.
2. Cold mirror or spatula test
Hold a clean, cool, smooth metal mirror or spatula just beneath the nostrils without touching the skin. During gentle nasal expiration, observe the area of condensation from each side. Compare the size and symmetry of the misting. Repeat only if the patient can breathe comfortably and the first observation is unclear.
- More symmetric misting: suggests broadly similar expired airflow at that moment.
- Reduced misting on one side: may suggest reduced airflow, but it does not identify whether the cause is mucosal, structural or due to technique.
- No clear mist: may reflect a warm or dry surface, weak expiration, mouth breathing or poor cooperation; it is not proof of complete obstruction.
The test is a quick qualitative screen, not a calibrated measurement. Warm the room-temperature plate only enough to make it comfortable; never use a hot surface. Keep it outside the nose and clean it between patients. Mouth breathing, forceful or inconsistent exhalation, ambient humidity and a recent spray can change the pattern.
3. Cotton-wool movement test
Hold a small, clean wisp of cotton outside one nostril and observe whether it moves during quiet breathing. Compare the other side under similar conditions. The cotton remains outside the nostril: do not push fibres into the vestibule, use loose material close to an uncooperative child, or perform the test where the fibres could be inhaled.
Reduced movement may reflect lower airflow on that side, but it is affected by distance, cotton size, room air currents and breathing effort. Describe what was observed rather than reporting a numerical result.
4. Gentle nostril support (Cottle-type manoeuvre)
A clinician may gently support the cheek or lateral nasal wall to see whether the patient reports improved airflow. This can suggest that lateral wall support affects the sensation of obstruction, but the manoeuvre is subjective and is not specific for one anatomical diagnosis. Avoid forceful traction or presenting a positive response as proof that surgery is required.
Objective and specialist measures
| Method | What it assesses | Role and limitations |
|---|---|---|
| Peak nasal inspiratory flow (PNIF) | Peak flow achieved through the nose during a forceful inspiration using a face mask and flow meter. | Can provide a repeatable, simple measure when technique, device and position are standardised. It is effort-dependent and does not show the anatomical site of obstruction. |
| Rhinomanometry | Relationship between nasal airflow and pressure, used to estimate nasal airway resistance. | Provides a more objective physiological assessment in specialist settings. Results depend on technique, equipment, cycle phase and mucosal state. |
| Acoustic rhinometry | Uses reflected sound to estimate changes in nasal cross-sectional area and volume along the passage. | Gives anatomical geometry rather than a direct measure of the patient’s perceived breathing. It requires appropriate equipment and interpretation. |
| Nasal endoscopy | Direct visual assessment of deeper nasal structures and the nasopharynx. | Can help identify a cause of obstruction, such as mucosal disease, polyps or a mass. It is an examination, not a stand-alone airflow measurement, and requires consent, training and suitable equipment. |
For PNIF, follow the meter manufacturer’s method and local clinical protocol. The patient generally seals the mask over the nose and mouth and inhales forcefully through the nose; record the best acceptable result and the device used. Do not compare numbers obtained with different devices or techniques as if they were interchangeable. Specialist tests may include measurements before and after a clinician-directed nasal decongestant or other challenge.
Interpreting findings with the examination
Consider visible secretions, mucosal swelling, turbinate enlargement, septal deviation, trauma or a foreign body. The simple test cannot distinguish these causes. Inspect gently with appropriate light and arrange further assessment if the history or findings warrant it.
Diffuse mucosal inflammation, bilateral secretions or the testing conditions may contribute. Compare the patient’s symptom report with observation and examination. Do not assume that a normal misting pattern rules out clinically important nasal disease.
Perceived obstruction and measured airflow can diverge. Recheck the method, timing and cooperation; ask about fluctuation; and consider whether formal assessment is needed. Avoid dismissing symptoms because a bedside test appears normal.
Anterior rhinoscopy or endoscopy may reveal an anatomical or mucosal explanation. Specialist interpretation may combine symptoms, examination and objective measurements. A single bedside test cannot diagnose allergic rhinitis, sinus disease, septal deviation or a mass on its own.
Common errors and safer practice
| Error | Why it matters | Safer approach |
|---|---|---|
| Testing while the patient is crying, talking or breathing through the mouth | The airflow pattern may not represent nasal breathing. | Allow the patient to settle, explain the task and record when a reliable comparison is not possible. |
| Calling a small difference an obstruction | The nasal cycle and ordinary variation can make sides differ. | Describe the actual observation, repeat under comparable conditions if safe, and correlate with history and inspection. |
| Inserting cotton, a probe or a test device into the nostril | May cause trauma, bleeding, distress or aspiration of loose fibres. | Keep simple test items outside the nostril. Use instruments only for a justified examination by trained staff. |
| Using a warm mirror or changing the distance between nostrils | Condensation and cotton movement become difficult to compare. | Use a clean, comfortably cool surface at a consistent position and compare sides in the same way. |
| Using a bedside test to rule out a mass or serious disease | A qualitative airflow check cannot inspect the full nasal passage. | Arrange examination or referral when symptoms are persistent, progressive, unilateral or associated with bleeding or a visible lesion. |
Clinical examples
A student reports that alternating nostrils feel blocked at different times. A small difference in cotton movement is seen. Explain the limits of the test, ask about fluctuation and associated allergy symptoms, then correlate with examination rather than labelling one nostril permanently obstructed.
An adult reports progressively worsening obstruction on one side with occasional blood-stained discharge. A mirror test shows less mist on that side. This is not a diagnosis; the persistent unilateral history requires prompt clinical examination and appropriate referral.
A young child turns away from the test and begins to cry. Do not hold a mirror or cotton against the nostrils. Stop, reassure the child and involve the supervising clinician to decide whether observation or a different assessment is appropriate.
Documentation checklist
- Record the patient’s main symptom, side, duration, fluctuation and relevant associated features.
- State the test used: subjective nostril comparison, mirror/spatula, cotton movement, PNIF or specialist measurement.
- Document right and left findings, position, cooperation, breathing effort and any factors that may affect reliability.
- Record the nasal examination findings separately from the airflow test.
- State limitations, advice, escalation, referral or follow-up plan.
Clinical sequence: Take a focused history → observe breathing → compare sides with a gentle bedside method → inspect the nose → interpret the result in context → document uncertainty and escalate when indicated.
Quick self-test
- What is meant by nasal patency?
- How does a cold mirror test compare airflow?
- Why is cotton movement a qualitative rather than quantitative test?
- What does PNIF measure, and what is one important limitation?
- Can a normal bedside patency test exclude a unilateral nasal mass?
Suggested answers
- How freely air passes through each nasal passage.
- It compares condensation from expired air beneath each nostril.
- Distance, cotton size, room airflow and the patient’s effort affect movement.
- Peak nasal inspiratory flow; it is effort-dependent and does not locate the obstruction.
- No. Persistent or concerning unilateral symptoms need appropriate examination and referral.
Key points
- Bedside nasal patency checks compare airflow; they do not establish a diagnosis.
- History, inspection and patient symptoms must be interpreted together.
- Mirror and cotton-wool tests are simple qualitative methods with important limitations.
- PNIF, rhinomanometry and acoustic rhinometry require standardised technique and appropriate interpretation.
- Keep simple test items outside the nostril and stop if the patient is distressed.
- Persistent unilateral obstruction, bleeding, trauma, a suspected foreign body or breathing difficulty requires escalation.
References and further reading
- Scadding GK, et al. Diagnostic tools in Rhinology: EAACI position paper. Clinical and Translational Allergy. 2011.
- National Health Systems Resource Centre, India. ENT Care Training Manual for Community Health Officers.
- Rimmer J, et al. A UK survey of current ENT practice in the assessment of nasal patency. Journal of Laryngology & Otology. 2017.
Class notes: Coming soon.
Educational note: This page is for medical education and revision. It does not replace supervised clinical skills training, local protocols, specialist advice or emergency assessment by a qualified clinician.
