About this symptom
Nasal congestion is a symptom of restricted airflow through the nose, not a diagnosis. It may follow a respiratory infection, allergy, non-allergic rhinitis or an anatomical obstruction.
What matters most
Note whether one or both nostrils are blocked, whether the side changes, how long symptoms persist and whether decongestant sprays are used regularly. In children, mouth breathing, snoring and disturbed sleep provide additional clues.
Symptoms and reasons to seek help
People report blockage on one or both sides, runny nose, reduced smell, facial pressure, mouth breathing or poor sleep. Alternating obstruction can reflect the normal nasal cycle, although inflammation may make it more noticeable.
Distinguishing similar conditions
Constant one-sided obstruction raises different questions from congestion that moves between nostrils. Green discharge alone does not establish bacterial sinusitis, and congestion does not automatically mean a deviated septum.
How clinicians investigate
An ENT clinician examines the nose and mucosa, reviews infections, trauma, triggers, medication and decongestant use. Nasal endoscopy may help when a routine examination cannot adequately assess the nasal passages or nasopharynx.
Care and important limitations
Care targets the identified cause: inflammation, allergy and structural narrowing are not treated identically. Prolonged unsupervised use of vasoconstrictor decongestant sprays can itself sustain congestion. Avoid self-prescribing antibiotics for the colour of mucus.
When emergency help is needed
Urgent assessment is needed for swelling around the eye with visual changes, severe headache with systemic illness or significant breathing difficulty. Call 103 or 112 if breathing is threatened or the person is critically unwell.
Related information
Deviated nasal septum; Sinusitis (maxillary sinusitis); Adenoids in children.
Signs and symptoms
People report blockage on one or both sides, runny nose, reduced smell, facial pressure, mouth breathing or poor sleep. Alternating obstruction can reflect the normal nasal cycle, although inflammation may make it more noticeable.
Diagnosis and tests
An ENT clinician examines the nose and mucosa, reviews infections, trauma, triggers, medication and decongestant use. Nasal endoscopy may help when a routine examination cannot adequately assess the nasal passages or nasopharynx.
Care and treatment approaches
Care targets the identified cause: inflammation, allergy and structural narrowing are not treated identically. Prolonged unsupervised use of vasoconstrictor decongestant sprays can itself sustain congestion. Avoid self-prescribing antibiotics for the colour of mucus.
When to seek urgent care
Urgent assessment is needed for swelling around the eye with visual changes, severe headache with systemic illness or significant breathing difficulty. Call 103 or 112 if breathing is threatened or the person is critically unwell.
Frequently asked questions
Why does one nostril become blocked and then the other?
The normal nasal cycle and changing mucosal swelling can cause this pattern; persistent troublesome symptoms need assessment.
Does green nasal mucus mean antibiotics are needed?
No. Discharge colour alone cannot identify a bacterial infection or justify antibiotic treatment.
When is nasal endoscopy appropriate?
When the clinician needs a clearer view of structures that are not adequately assessed during a standard examination.
Important information
A medical consultation is needed for diagnosis and treatment recommendations.
Self-treatment can be harmful to your health.
