One-sided nasal blockage can be caused by a deviated septum, enlarged structures inside the nose, a polyp, inflammation, or a temporary nasal cycle. Persistent or progressive blockage on only one side deserves assessment because less common causes may need to be excluded, particularly when bleeding or facial symptoms accompany it.
Common explanations
The normal nasal cycle means one side may feel more open than the other at different times. Allergies, viral inflammation, septal deviation, and turbinate enlargement can also cause obstruction. A foreign body is a consideration in children, especially if blockage is accompanied by foul-smelling discharge from one side.
How the cause is assessed
A clinician asks about duration, previous injuries or surgery, allergies, smell changes, bleeding, discharge, and facial pain. Examination may include looking inside the nose; nasal endoscopy or imaging may be recommended if symptoms persist or findings need clarification. Treatment depends on the cause, not just the sensation of blockage.
Warning signs to report
Arrange timely assessment for ongoing one-sided obstruction, recurrent bleeding, bloody or foul discharge, a visible lump, facial numbness, or worsening pain. Seek urgent care after trauma if there is major bleeding, deformity, or concern for a septal haematoma. New eye symptoms or severe neurological symptoms also need urgent review.
Frequently asked questions
Can a deviated septum block one nostril? Yes, although symptoms can also reflect swelling, allergies, or other causes.
Should I use decongestant spray every day? Do not use topical decongestant sprays longer than the label or clinician recommends because prolonged use may worsen congestion.
Does one-sided blockage mean cancer? Usually not, but persistent one-sided symptoms and associated bleeding or a mass should be examined rather than ignored.
Explore our ENT consultation page for more information about this care option. A clinician can advise based on the individual history and examination findings.
Related reading
- Deviated Septum: Symptoms, Diagnosis and Treatment Options
- Nasal Endoscopy: What Happens During an ENT Examination?