The nasal cycle: why one side is often more blocked
Every few hours, the lining of one nostril swells slightly while the other shrinks, and then they swap. Most people do not notice because total airflow stays constant. When you have a cold, allergy or structural narrowing, the difference becomes obvious. Lying on one side makes the lower nostril more blocked because of gravity and blood pooling. This is normal and not a disease. See blocked nose at night and stuffy nose.
Causes of a persistently blocked nostril
- Deviated nasal septum: the wall between the nostrils is bent, narrowing one side; present from birth or after injury.
- Enlarged turbinates: swollen structures on the side wall of the nose from allergy or chronic rhinitis. See chronic rhinitis.
- Nasal polyps: soft, painless growths from the lining. See nasal polyps.
- Chronic sinusitis. See sinus infection symptoms.
- Concha bullosa (an air-filled turbinate) and other anatomical variants.
- Foreign body, particularly in children.
- Previous nasal injury or surgery, scar tissue or septal haematoma.
- Rebound congestion from decongestant sprays.
- Nasal valve collapse, with the side of the nose sucking in on breathing.
- Tumours (benign or malignant), rare.
Clues to the cause
- Blocked since a nose injury: think deviated septum or scarring.
- Blocked with itchy, sneezy symptoms and seasonal changes: allergy and turbinate swelling.
- Blocked with loss of smell and thick discharge: polyps or chronic sinusitis.
- Blocked with nosebleeds, one-sided pain or numbness: needs prompt examination.
- Blocked with a foul smell from one side in a child: foreign body.
- Blocked when breathing in deeply, with the nostril collapsing: nasal valve problem.
- Alternating blockage that is mild and comes and goes: nasal cycle.
What to try at home
- Rinse with saline once or twice a day. See neti pot sinus rinse.
- Use a steroid nasal spray daily for allergy or chronic swelling, aimed away from the septum.
- Take an antihistamine if allergy is likely.
- Use steam, a warm shower or a humidifier.
- Sleep with your head raised and on the side of the clearer nostril.
- Try external nasal strips or internal dilators if the nasal valve is weak.
- Avoid decongestant sprays for more than 3 days.
- Avoid smoke and irritants.
Medical treatment
- Nasal endoscopy in clinic to see the septum, turbinates, polyps and drainage.
- Medicines: steroid sprays, antihistamines, short courses of oral steroids for polyps.
- Allergy testing and immunotherapy if allergy is significant.
- Turbinate reduction (radiofrequency, coblation or partial resection) for swollen turbinates.
- Septoplasty to straighten a deviated septum; sometimes combined with turbinate surgery.
- Polyp removal and sinus surgery for chronic sinusitis.
- Nasal valve surgery or implants for collapse.
- CT scan or biopsy when a mass is suspected.
Blockage, snoring and sleep
A persistently blocked nostril can contribute to mouth breathing, dry mouth, snoring and poor sleep, and in some people to obstructive sleep apnea. Treating the nasal obstruction often improves comfort and snoring, though it may not cure sleep apnea. See mouth breathing and snoring with mouth closed.
Children with one blocked nostril
In a child, one-sided blockage with a foul-smelling, sometimes bloody discharge strongly suggests a foreign body such as a bead, small toy, food or paper. Do not try to remove it with tweezers or cotton buds, as it can be pushed deeper; see a doctor promptly. Other causes include adenoid enlargement, allergy and colds.
When to see a doctor
- Blockage on one side lasting more than 4 weeks.
- Blockage with bleeding, foul smell, facial pain, numbness or swelling.
- Loss of smell or taste.
- Blockage after injury.
- A child with one-sided smelly discharge.
- Recurrent sinus infections.
- Dependence on decongestant sprays.
- A lump in the nose or neck, or double vision: urgent.
Three common situations
An adult with a left blocked nostril since a sports injury: likely deviated septum; ENT assessment and possible septoplasty.
A person with a blocked side and loss of smell for months: consider polyps or chronic sinusitis.
A toddler with a smelly discharge from one nostril: see a doctor to exclude a foreign body.
Key points to remember
A nostril that shifts sides is normal; one that is always blocked deserves examination. Rinse, use a steroid spray and avoid decongestants while arranging assessment for persistent, one-sided or bloody symptoms. Our ENT team can examine your nose and plan treatment.
This guide is for general information and does not replace an examination by your own doctor, dentist or ENT specialist.
Questions about one nostril always blocked
These answers are general information and do not replace an examination or individual medical advice.
Why is only one nostril blocked?
It may be the nasal cycle, or a deviated septum, swollen turbinate, polyps or sinus disease.
Is it normal for nostrils to alternate?
Yes, the nasal cycle alternates swelling every few hours.
When is a blocked nostril serious?
With bleeding, foul smell, facial pain, numbness, a lump or after injury.
How do I unblock one nostril at home?
Saline rinse, steroid spray, steam and sleeping on the opposite side.
Will I need surgery?
Only if a structural problem such as a deviated septum or polyps does not respond to medicine.
What if my child has a blocked nostril?
See a doctor if discharge is smelly or bloody, since a foreign body is likely.
Sources
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.