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Health condition · Clinically reviewed

Chronic sinusitis, chronic rhinosinusitis, with and without polyps.

Symptoms lasting more than 12 weeks — nasal blockage, discharge, facial pressure, loss of smell. Medical treatment first, functional endoscopic sinus surgery (FESS) for refractory disease.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Every claim is checked against EPOS 2020, NICE and specialist society sources you can see at the end.

  • 03

    Current for 2026

    Reflects EPOS 2020 endotype-driven care and the current place of biologics in severe CRSwNP.

Key facts

Chronic sinusitis at a glance.

The essentials, in plain English — the two phenotypes, the endotype behind them, and what shapes treatment from spray to biologic to surgery.

  • What it is

    Rhinosinusitis lasting more than 12 weeks — inflammation of the nose and paranasal sinuses with two or more cardinal symptoms.

  • Two phenotypes

    CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP) — a critical split that shapes treatment.

  • Endotype-driven care

    EPOS 2020 encourages classification by inflammatory endotype (type 2 vs non-type 2), guiding biologic selection.

  • First-line treatment

    Intranasal corticosteroids (mometasone, fluticasone) plus saline irrigation are foundational for both phenotypes.

  • Biologics for severe

    Dupilumab, omalizumab and mepolizumab are licensed for severe CRSwNP where medical therapy and surgery fall short.

  • Surgery when needed

    Functional endoscopic sinus surgery (FESS) is offered for refractory obstruction after appropriate medical treatment.

Why this guide matters

Not just a bad cold — a treatable long-term condition.

Chronic rhinosinusitis is often under-treated. The three points below shape everything else on this page.

  • Phenotype guides the plan

    CRS with polyps and CRS without polyps behave differently — and are treated differently.

  • Endotype is the new lens

    EPOS 2020 asks not just what it looks like, but what drives it — type 2 disease responds to biologics.

  • Surgery is not the finish line

    FESS restores drainage; long-term steroid spray and saline keep the disease at bay.

How the diagnosis is made

From long-standing symptoms to a clear plan.

The steps a UK GP and ENT team will normally follow, in order — so you know what to expect and why.

  1. 01

    Recognising

    Symptom review (>12 weeks)

    Nasal blockage, discharge, facial pain or pressure, and reduced sense of smell — persisting more than 12 weeks.

  2. 02

    Recognising

    Nasal endoscopy

    Direct inspection of the nose and sinus openings to identify polyps, pus and mucosal inflammation.

  3. 03

    Recognising

    CT sinuses (if surgery planned)

    Reserved for refractory disease when surgery is being considered — maps anatomy and disease burden.

  4. 04

    Confirming

    Allergy testing when indicated

    Skin-prick or specific IgE testing where an allergic driver is suspected.

  5. 05

    Confirming

    Asthma / NSAID sensitivity screen

    Screen for asthma and aspirin-exacerbated respiratory disease (Samter’s triad) — common co-travellers with CRSwNP.

  6. 06

    Managing

    ENT rhinology referral

    Referral to a rhinology service when disease fails to respond to appropriate medical therapy.

  7. 07

    Managing

    Baseline SNOT-22 quality-of-life

    A validated symptom score used to measure baseline burden and monitor treatment response over time.

Typical timeline: 6–12 weeks from first review to a settled plan.

Symptoms

What chronic sinusitis actually looks like.

Two or more cardinal symptoms for more than 12 weeks — with one being nasal blockage or discharge. Here are the patterns that matter.

  • Nasal blockage

    Persistent congestion or obstruction of one or both sides of the nose.

  • Mucopurulent discharge

    Thick discharge from the front of the nose or dripping down the back of the throat.

  • Facial pain / pressure

    Aching or heaviness across the cheeks, forehead or between the eyes.

  • Reduced sense of smell

    Hyposmia or complete loss of smell — a hallmark of CRSwNP.

  • Nasal polyps

    Soft, painless swellings inside the nose seen on endoscopy — the defining feature of CRSwNP.

  • Aspirin-sensitive (Samter’s triad)

    Asthma, nasal polyps and aspirin/NSAID intolerance travelling together — a distinct endotype.

  • Asthma comorbidity

    Asthma and CRSwNP frequently coexist and worsen one another — treat the airway as a whole.

  • Red flag

    Unilateral bloody discharge with facial numbness — urgent ENT and imaging to exclude sinonasal tumour.

Treatment

How chronic sinusitis is treated in the UK.

Medical care first, biologics for severe type 2 disease, and FESS for refractory obstruction — what each option does, and where it belongs in the plan.

  • Nasal saline irrigation

    Large-volume saline rinses clear mucus and inflammatory debris — a low-cost foundation for every plan.

  • Intranasal corticosteroid

    Mometasone or fluticasone sprays reduce mucosal inflammation and polyp size — used daily and long-term.

  • Oral corticosteroid (short-course)

    A short course for severe polyp disease to shrink polyps and rescue symptoms — not for long-term use.

  • Long-term macrolide (specific cases)

    Low-dose macrolides for selected non-type 2 CRSsNP patients with persistent symptoms after standard therapy.

  • Biologic (dupilumab, omalizumab, mepolizumab)

    Monoclonal antibodies for severe CRSwNP with type 2 inflammation, when medical and surgical care are insufficient.

  • Balloon sinuplasty

    A minimally invasive option to open selected sinus outflow tracts — chosen for specific anatomies.

  • Functional endoscopic sinus surgery (FESS)

    Endoscopic surgery to restore drainage and remove polyps in refractory disease — followed by ongoing medical therapy.

  • Aspirin desensitisation (AERD)

    A structured protocol for aspirin-exacerbated respiratory disease that can reduce polyp recurrence.

What this guide is based on

The sources behind every claim on this page.

European and UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or ENT specialist knows your history and can tell you which parts apply to you.

  • EPOS 2020 — European Position Paper on Rhinosinusitis and Nasal Polyps.

  • NICE. Sinusitis (acute and chronic): Clinical Knowledge Summary.

  • ENT UK. Chronic rhinosinusitis guidance and patient information.

  • British Society of Allergy and Clinical Immunology (BSACI). Rhinosinusitis guidelines.

Red flags

When sinusitis points to something else.

Most chronic sinusitis is managed medically. These are the situations that need urgent ENT input or emergency care.

  • Unilateral bloody discharge

    One-sided bleeding or blood-stained discharge warrants urgent ENT assessment to exclude a sinonasal tumour.

  • Facial numbness / diplopia

    Loss of sensation or double vision suggests spread beyond the sinus — needs urgent imaging.

  • Orbital cellulitis

    Eye swelling, proptosis or pain on eye movement is an emergency — same-day ENT and ophthalmology review.

  • Frontal-lobe symptoms

    Confusion, drowsiness or seizures raise concern for intracranial extension — call 999.

  • CSF rhinorrhoea

    Clear watery fluid from one nostril, especially after trauma or surgery — needs urgent ENT / neurosurgical review.

  • Bone erosion on CT

    Erosion of sinus walls on imaging suggests an aggressive process — invasive fungal disease or tumour must be excluded.

  • Aspergilloma

    A fungal ball within a sinus — often incidental on CT, but may require surgical clearance.

  • Wegener’s / GPA sinus involvement

    Crusting, septal perforation and systemic symptoms may signal granulomatosis with polyangiitis — rheumatology referral.

  • Post-op complications

    New severe pain, bleeding, visual change or CSF leak after sinus surgery needs urgent contact with the surgical team.

Living with it

A long-term condition, but a very manageable one.

Four things that make the biggest difference day to day — saline rinsing, correct spray technique, joined-up airway care, and steady follow-up.

A quiet reminder

Consistency beats intensity, every time.

Daily rinsing and correct steroid-spray technique, kept up for months, do more than any short burst of treatment.

  1. 01 Rinsing

    Saline daily, forever

    Twice-daily large-volume saline rinses are the single most useful long-term habit for CRS.

  2. 02 Spray

    Steroid spray, correct technique

    Aim the spray outwards, away from the septum. Consistency over months matters more than dose.

  3. 03 Airway

    Treat asthma alongside

    CRSwNP and asthma share an inflammatory pathway — well-controlled asthma helps the nose.

  4. 04 Follow-up

    Review, don’t drift

    Regular ENT review keeps the plan on track and catches polyp regrowth early after surgery.

Frequently asked

Everything we get asked about chronic sinusitis.

Quick answers on phenotypes, biologics, FESS and Samter’s triad.

  • When does sinusitis become “chronic”?

    When rhinosinusitis symptoms — nasal blockage, discharge, facial pressure or reduced smell — persist for more than 12 weeks. Shorter episodes are classed as acute or recurrent acute sinusitis.

  • What’s the difference between CRSwNP and CRSsNP?

    CRSwNP has visible nasal polyps on endoscopy and is more often type 2 inflammatory; CRSsNP has no polyps and is more heterogeneous. The split guides treatment, including whether biologics are appropriate.

  • Do I always need a CT scan?

    No. CT sinuses is reserved for cases where surgery is being considered or complications are suspected — not for routine diagnosis.

  • How do biologics like dupilumab work?

    They are monoclonal antibodies that block key drivers of type 2 inflammation (such as IL-4, IL-5 or IgE), shrinking polyps and improving symptoms in severe CRSwNP that has not responded to standard care.

  • Is FESS a permanent fix?

    FESS restores sinus drainage and removes polyps, but underlying inflammation continues. Ongoing intranasal steroid and saline irrigation are essential to prevent recurrence.

  • What is Samter’s triad?

    Aspirin-exacerbated respiratory disease (AERD): the combination of asthma, nasal polyps and reactions to aspirin or other NSAIDs. It responds well to biologics and, in selected patients, aspirin desensitisation.

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