Introduction
The nasal cycle refers to the spontaneous and reciprocal congestion and decongestion of the nasal mucosa, primarily involving the inferior turbinates, leading to alternating airflow dominance between the two nasal cavities.Reference Hanif, Jawad and Eccles1 This process is regulated by autonomic control of the nasal venous sinusoids and is considered a normal physiological phenomenon in healthy individuals. Although initially described over a century ago, the nasal cycle remains a concept largely confined to physiological and experimental literature.Reference Wojas, Szczêsnowicz-Dąbrowska, Krzych-Fałta, Samel-Kowalik, Samoliński and Grzanka2
In routine clinical practice, patients frequently present with complaints of unilateral or alternating nasal obstruction.Reference Kahana-Zweig, Geva-Sagiv, Weissbrod, Secundo, Soroker and Sobel3 Such symptoms are often perceived as pathological, leading to anxiety, inappropriate use of topical nasal medications and repeated healthcare consultations. The inability to distinguish between normal physiological variation and disease may contribute to symptom amplification and unnecessary investigations or interventions.Reference Li, Yu, Li, Qian, Song and Gao4
Despite the clinical relevance of the nasal cycle, there is a lack of literature evaluating patient awareness and understanding of this phenomenon.Reference Stewart, Witsell, Smith, Weaver, Yueh and Hannley5 Assessing how patients perceive and interpret normal nasal physiology is essential for improving counselling strategies and promoting rational management.Reference Hernandez, Uhl, Haehner, Cuevas and Hummel6 This study aimed to evaluate patient awareness of the nasal cycle and its association with symptom severity and anxiety in an outpatient otolaryngology population.Reference Min7
Materials and methods
This prospective observational study was conducted in the general otolaryngology outpatient clinic of a tertiary care teaching hospital over a four-month period. Adult patients aged 18 years and above attending the outpatient clinic for nasal or non-nasal otolaryngological complaints were consecutively recruited. Patients were consecutively recruited from general otolaryngology outpatient clinics, including both routine and urgent (two-week wait) referrals, where applicable. All eligible adult patients aged greater than or equal to 18 years presenting during the study period were considered for inclusion to minimise selection bias.
Patients with acute rhinosinusitis, nasal polyposis, recent nasal surgery within three months or gross deviated nasal septum causing fixed obstruction were excluded. Written informed consent was obtained from all participants prior to inclusion.
This study was conducted in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments. Institutional ethics committee approval was obtained prior to commencement of the study. Written informed consent was obtained from all individual participants included in the study
Participants completed a structured questionnaire designed to assess awareness of the nasal cycle, perception of alternating nasal obstruction, interpretation of such symptoms as normal or abnormal and associated anxiety using a Likert scale. The questionnaire was developed by the authors based on common clinical presentations and was reviewed for face validity by two consultant otolaryngologists prior to use. However, formal validation was not performed.
Anxiety related to nasal symptoms was assessed using a simple Likert scale (ranging from “not at all” to “severe”). Although this was not a formally validated anxiety instrument, it was designed to capture symptom-specific anxiety relevant to nasal obstruction in a pragmatic outpatient setting. Nasal symptom severity was assessed using the validated Nasal Obstruction Symptom Evaluation (NOSE) score. Objective assessment of nasal airflow dominance was performed using the cold spatula test under standardised outpatient conditions (Appendix 1).
Assessment of nasal and allergic comorbidities
In addition to demographic details, data regarding nasal and allergic comorbidities were recorded. This included a history of allergic rhinitis based on prior diagnosis or typical symptom history, previous nasal or sinus surgery performed more than three months prior to presentation, current use of topical nasal medications (intranasal corticosteroids, antihistamine sprays or topical decongestants) and ongoing systemic allergy treatment. These variables were documented to assess their potential influence on nasal symptom perception and awareness of the nasal cycle.
Objective assessment
Anterior nasal valve competence was assessed clinically during routine anterior rhinoscopy. Patients with clinically evident nasal valve collapse or other fixed structural causes of nasal obstruction were excluded from the study to minimise confounding effects on symptom perception.
Although the cold spatula test is a relatively simple and indirect method of assessing nasal airflow, it was selected due to its practicality in a busy outpatient setting and its widespread use in routine clinical practice.
As this was an exploratory observational study, a formal sample size calculation was not performed. A target sample size of 120 patients was considered adequate based on feasibility and similar studies in outpatient settings.
Statistical analysis was performed using standard statistical software. Continuous variables were expressed as mean ± standard deviation and categorical variables as frequencies and percentages. Associations between nasal cycle awareness and clinical variables were analysed using the chi-squared test. Multivariate logistic regression analysis was performed to identify independent predictors of poor nasal cycle awareness. A p-value of less than 0.05 was considered statistically significant.
Results
A total of 120 patients were included in the final analysis. The mean age of the study population was 36.8 ± 12.4 years, with a slight male predominance. Nasal symptoms were present in 70 per cent of participants, while the remaining patients attended the clinic for non-nasal otolaryngological complaints. The mean NOSE score for the cohort was 38.6 ± 18.2, reflecting a broad spectrum of symptom severity (Table 1).
Demographic and clinical characteristics of study participants (n = 120)
Table 1 Long description
Participant demographics and clinical measures are summarized for 120 people. The average age was 36.8 years with a spread of 12.4 years. There were 68 males (56.7 percent) and 52 females (43.3 percent), indicating a modest male majority. Nasal symptoms were present in 84 participants (70 percent), so symptoms were common in this group. The mean NOSE score was 38.6 with a spread of 18.2, suggesting moderate symptom burden on average with substantial variability. Percentages are based on the full sample size, and the averages do not show how scores are distributed across individuals.
Awareness of the nasal cycle as a normal physiological process was present in only 34 patients (28.3 per cent), whereas the majority of participants (71.7 per cent) were unaware of this concept. Despite this limited awareness, 62 patients (51.7 per cent) reported experiencing alternating nasal obstruction at different times of the day. Among these patients, 41 (66.1 per cent) perceived the alternating obstruction as abnormal or indicative of disease (Table 2).
Patient awareness and perception of the nasal cycle
Table 2 Long description
Patient awareness of the nasal cycle and perceptions of alternating nasal blockage are reported with counts and percentages. A large majority were unaware of the nasal cycle, with 86 patients (71.7 percent), compared with 34 (28.3 percent) who were aware. Just over half reported perceiving alternating nasal obstruction, 62 patients (51.7 percent). About one third considered alternating obstruction abnormal, 41 patients (34.2 percent). Awareness of the nasal cycle is notably lower than the proportion who notice alternating obstruction. It is not indicated whether the same individuals appear in multiple rows, so relationships between awareness and perceptions cannot be determined from these figures alone.
Patients who were unaware of the nasal cycle demonstrated significantly greater nasal symptom burden. The mean NOSE score in unaware patients was 42.1 ± 17.6 compared with 30.4 ± 15.8 among those who were aware of the nasal cycle (p = 0.01). Symptom-related anxiety was also significantly higher in the unaware group, with a greater proportion reporting moderate to severe anxiety (p = 0.003) (Table 3).
Association between nasal cycle awareness and clinical variables
Table 3 Long description
Clinical measures are compared between people who were aware of their nasal cycle (34 participants) and those who were unaware (86 participants), along with p-values for group differences. Mean NOSE score was lower in the aware group (30.4 with a spread of 15.8) than in the unaware group (42.1 with a spread of 17.6), with a p-value of 0.01. High anxiety scores were less common among aware participants (6 people, 17.6 percent) than among unaware participants (49 people, 57.0 percent), with a p-value of 0.003. Prior ENT consultation was more common in the aware group (21 people, 61.8 percent) than in the unaware group (29 people, 33.7 percent), with a p-value of 0.02. Overall, unawareness is associated with higher symptom burden and higher anxiety, while awareness is associated with more prior ENT consultation. The p-values indicate statistically significant differences, but effect sizes are not provided and potential confounders are not adjusted for, so causation cannot be inferred.
Prior consultation with an otolaryngologist was associated with better awareness of the nasal cycle. On multivariate logistic regression analysis, absence of prior ENT consultation and higher anxiety scores emerged as independent predictors of poor nasal cycle awareness. These findings suggest that lack of physiological understanding contributes to heightened symptom perception and anxiety in patients with nasal complaints.
Allergic rhinitis was the most common comorbidity, present in 38.3 per cent of participants. Approximately one-quarter of patients were using intranasal corticosteroids at the time of evaluation. Despite the presence of nasal and allergic comorbidities, awareness of the nasal cycle remained low across subgroups, suggesting that lack of physiological understanding rather than comorbidity alone contributed to symptom misinterpretation (Table 4).
Nasal and allergic comorbidities of study participants (n = 120)
Table 4 Long description
Summary of nasal and allergy-related conditions and treatments reported by 120 study participants, listing counts and percentages for each item. The most common finding was no topical nasal medication use, reported by 55 participants (45.8 percent). Allergic rhinitis was also frequent, affecting 46 participants (38.3 percent). Current intranasal steroid use was reported by 32 participants (26.7 percent), and ongoing systemic allergy treatment by 24 participants (20.0 percent). Smaller proportions used topical nasal decongestants (21, 17.5 percent) or intranasal antihistamines (18, 15.0 percent). Prior nasal or sinus surgery more than 3 months earlier was reported by 14 participants (11.7 percent). Categories may overlap because individuals can have a condition and use one or more treatments, so percentages are not intended to add up to a total.
Predictors of poor nasal cycle awareness
Multivariate logistic regression analysis was performed to identify independent predictors of poor awareness of the nasal cycle. Variables entered into the model included age, sex, presence of nasal symptoms, NOSE score, anxiety level, prior ENT consultation, allergic rhinitis and use of topical nasal medications. Absence of prior ENT consultation and higher anxiety scores emerged as independent predictors of poor nasal cycle awareness. Allergic rhinitis, prior nasal surgery and topical nasal medication use did not independently predict awareness status (Table 5).
Multivariate logistic regression analysis predicting poor nasal cycle awareness
Table 5 Long description
Adjusted odds ratios with 95 percent confidence intervals and p-values are reported for factors predicting poor nasal cycle awareness. High anxiety score shows higher odds, with an odds ratio of 3.41 and a p-value of 0.003. No prior ENT consultation also shows higher odds, with an odds ratio of 2.84 and a p-value of 0.009. Presence of nasal symptoms has an odds ratio of 1.32 with a p-value of 0.48, suggesting no clear association. Allergic rhinitis has an odds ratio of 1.18 with a p-value of 0.67, and intranasal steroid use has an odds ratio of 0.91 with a p-value of 0.82, both not clearly associated. Prior nasal or sinus surgery has an odds ratio of 1.09 with a p-value of 0.88, also not clearly associated. Confidence intervals for the non-significant factors include values consistent with no effect, so their direction and size are uncertain in this model.
Discussion
This study demonstrates that patient awareness of the nasal cycle is remarkably low in an outpatient otolaryngology population. Although more than half of the participants perceived alternating nasal obstruction, the majority interpreted this normal physiological phenomenon as pathological. Patients lacking awareness reported greater symptom severity and anxiety, highlighting the psychological impact of misinterpreting normal nasal physiology.
• The nasal cycle is a normal physiological phenomenon causing alternating nasal airflow dominance.
• Patients commonly present with complaints of unilateral or alternating nasal obstruction, which may generate anxiety and repeated consultations.
• Most patients are unaware of the nasal cycle and frequently misinterpret normal nasal physiology as disease.
• Poor awareness is associated with higher nasal symptom severity and increased anxiety, independent of structural or allergic pathology.
• Simple physiological counselling during outpatient visits may reduce anxiety and unnecessary treatment.
Clinical implications and strategies to improve patient Awareness
The findings of this study have important clinical implications for routine otolaryngology practice. Misinterpretation of the physiological nasal cycle as pathological nasal obstruction may lead to unnecessary anxiety, inappropriate use of topical decongestants, repeated outpatient visits and unwarranted investigations. Patients unaware of the nasal cycle demonstrated significantly higher symptom burden and anxiety, highlighting the psychological amplification of symptoms when normal physiology is misunderstood.Reference Eccles8
Simple physiological counselling explaining the nasal cycle during outpatient consultations represents a low-cost, high-impact intervention. Such counselling may reduce symptom-related anxiety, improve patient reassurance and promote rational use of medications. Current management guidelines for nasal obstruction and rhinitis focus largely on symptom control and structural pathology but rarely address physiological airflow variation. Integrating brief education regarding the nasal cycle into routine clinical assessment may improve patient understanding and optimise management decisions.
Future studies incorporating objective airflow measurements such as rhinomanometry and validated psychological assessment tools may further strengthen the understanding of patient perception of the nasal cycle.
Strengths and limitations
The strengths of this study include its prospective design, outpatient-based population and use of a validated symptom scoring system. The study addresses an underexplored aspect of nasal physiology by focusing on patient awareness rather than objective measurement alone. However, limitations include the single-center design and the absence of advanced objective airflow measurement techniques. Objective airflow assessment was performed using the cold spatula test, which is less precise than rhinomanometry or acoustic rhinometry; however, it reflects real-world outpatient practice. The absence of a formal sample size calculation may limit the statistical power of the multivariate analysis. The assessment of anxiety was based on a non-validated Likert scale rather than a standardised psychometric instrument, which may limit the precision of anxiety measurement. The cross-sectional nature of the study also limits causal inference.
Conclusion
Patient awareness of the nasal cycle is limited in the outpatient otolaryngology setting, and normal physiological nasal airflow alternation is frequently misinterpreted as disease. Lack of awareness is associated with higher symptom burden and increased anxiety, independent of nasal or allergic comorbidities. Absence of prior otolaryngology consultation and higher anxiety levels are key predictors of poor awareness. Incorporating brief physiological counselling regarding the nasal cycle into routine outpatient consultations may reduce anxiety, prevent unnecessary treatment and promote rational management of nasal symptoms.
Competing interests
The authors declare no conflict of interest.
Acknowledgment of AI assistance
The authors acknowledge the use of ChatGPT (OpenAI) for language editing and structuring of the manuscript. The authors retain full responsibility for the accuracy, integrity and originality of the content, including data analysis and interpretation.
Appendix 1: Nasal Cycle Awareness Questionnaire
1. Do you feel nasal blockage more on one side than the other?
☐ Yes ☐ No
2. Does the side of nasal blockage change during the day?
☐ Yes ☐ No ☐ Not sure
3. Before today, were you aware that nasal airflow normally alternates between sides?
☐ Yes ☐ No
4. Do you consider alternating nasal blockage abnormal?
☐ Yes ☐ No
5. Does this nasal blockage cause anxiety or worry?
☐ Not at all ☐ Mild ☐ Moderate ☐ Severe
6. Have you previously consulted an ENT specialist for nasal blockage?
☐ Yes ☐ No
7. Do you regularly use nasal sprays for this symptom?
☐ Yes ☐ No
