Overview
Nasal polyps are soft, painless, non-cancerous growths on the lining of the nasal passages or sinuses. They result from chronic inflammation. Small polyps may cause no symptoms, but larger polyps or clusters can block nasal passages, cause loss of smell, and lead to chronic sinusitis and breathing difficulties.
How common is it?
Nasal polyps mainly affect adults and are rare in children. They are associated with asthma and aspirin sensitivity and can return after treatment.
Causes and risk factors
Persistent mucosal inflammation triggers abnormal tissue proliferation and fluid accumulation, forming polypoid tissue. The precise mechanism involves type 2 inflammatory pathways.
Common risk factors
- Chronic rhinosinusitis
- Asthma
- Allergic rhinitis
- Aspirin-exacerbated respiratory disease (Samter's triad: asthma, nasal polyps, aspirin sensitivity)
- Cystic fibrosis
- Churg-Strauss syndrome (eosinophilic granulomatosis with polyangiitis)
- Non-allergic rhinitis with eosinophilia
Symptoms
- Persistent nasal congestion or blocked nose
- Anosmia or hyposmia (reduced or absent sense of smell)
- Runny nose
- Postnasal drip
- Facial pressure or pain
- Snoring and poor sleep
- Reduced taste
- Recurrent sinusitis
When to see a doctor
See a GP if persistent blockage or reduced smell suggests nasal polyps; do not wait three months if symptoms are troublesome. One-sided blockage, bleeding or an unusual growth needs prompt assessment. Severe breathing difficulty or new eye swelling/vision problems needs urgent care.
Diagnosis
Nasal endoscopy visualises polyps directly. CT sinuses assesses extent and sinus anatomy. Allergy testing. Nasal swabs for infection. Biopsy if unusual appearance or unilateral.
Treatments
Nasal corticosteroid sprays
First-line treatment. Fluticasone or mometasone sprays used correctly (aimed laterally, not at the septum) reduce polyp size and relieve symptoms in most cases. Used long-term. Proper technique is critical.
Short course of oral corticosteroids
A clinician may prescribe a short oral corticosteroid course when needed. Benefits may be temporary, and ongoing nasal treatment is often required. Steroids can raise blood glucose; people with diabetes should agree a monitoring plan.
Functional endoscopic sinus surgery (FESS)
Endoscopic surgery removes polyps and opens blocked sinuses when medical treatment is insufficient. Most people improve, but polyps often return within a few years. Ongoing nasal steroid treatment may reduce recurrence.
Biologic therapy (dupilumab)
Dupilumab is a specialist add-on to nasal steroids for selected adults with severe uncontrolled chronic rhinosinusitis with polyps. NICE eligibility includes previous sinus surgery and substantial ongoing symptoms. Benefits and risks need individual review.
Self-care and lifestyle
- Use nasal steroid spray every day, not just when symptomatic
- Saline rinsing can clear secretions; use sterile/distilled or previously boiled and cooled water and clean equipment.
- Avoid aspirin and NSAIDs if diagnosed with Samter's triad
- Treat underlying asthma and allergic rhinitis well
Prevention
Optimal control of asthma, allergic rhinitis, and prompt treatment of sinusitis may reduce polyp formation. There is no reliable primary prevention.
Sources for targeted updates
Updated: 24 October 2026. Targeted corrections to urgent-care guidance, treatment, self-care, key facts, frequency, risk factors. This update covers the named sections; a full review of the remaining guide is pending.