Defined by twelve weeks — not by a single bad infection.
Chronic rhinosinusitis (CRS) is inflammation of the lining of the nose and paranasal sinuses lasting twelve weeks or longer. It is distinct from an acute sinus infection, which typically follows a cold and resolves within ten to fourteen days. Roughly ten to twelve percent of American adults are affected — one of the most common chronic conditions in primary care, and one of the most under-evaluated.
CRS exists on a spectrum. On one end is CRS without nasal polyps (CRSsNP) — typically driven by mechanical obstruction of the sinus drainage pathways, sometimes layered with bacterial biofilm or fungal colonization. On the other end is CRS with nasal polyps (CRSwNP) — typically driven by an eosinophilic, Type 2 inflammatory cascade involving cytokines like IL-4, IL-5, and IL-13. The same word, "chronic sinusitis," describes both — but the treatment paths diverge meaningfully.
Getting the right diagnosis matters because it changes everything that comes after. A patient with polypoid disease, anosmia, asthma, and aspirin sensitivity is on a fundamentally different clinical pathway than a patient with deviated anatomy and recurrent bacterial infections.
When it's time to see a specialist.
The four cardinal symptoms of CRS — at least two of which need to be present for twelve weeks for the diagnosis — are:
- Nasal obstruction or congestion
- Facial pressure, fullness, or pain
- Mucopurulent nasal or post-nasal discharge
- Reduction or loss of smell (hyposmia or anosmia)
These often come with secondary effects: fatigue, dental pain mimicking molar disease, headaches that resist usual headache treatments, sleep disturbance, and reduced productivity. Patients commonly describe the experience as "feeling like I'm fighting a cold all the time" or "having a cold that never quite ends."
Specialist evaluation is appropriate when symptoms persist beyond twelve weeks, when over-the-counter and primary-care therapy hasn't worked, when there's a history of multiple antibiotic courses, when polyps are visible on exam, or when smell loss is part of the picture. Earlier evaluation is also appropriate for patients with asthma — CRS and asthma are linked enough that treating one improves the other.
A real exam, then the right imaging.
An accurate CRS diagnosis is anchored in three things: a focused history, nasal endoscopy in the office, and — when needed — a low-dose CT scan of the sinuses without contrast.
The history covers symptom timeline and severity, prior antibiotic courses, prior surgeries, allergies, asthma, aspirin sensitivity, and any prior workups. Most diagnoses come from the conversation, not the scan.
Nasal endoscopy — a brief, in-office examination with a small flexible camera — visualizes the middle meatus, the natural drainage pathway of the maxillary and ethmoid sinuses, and identifies polyps, purulence, post-surgical anatomy, and septal deviation. Endoscopy is the single most useful in-office tool for CRS and is performed during the same visit as the initial consultation.
CT imaging is ordered when the clinical picture warrants it — to map sinus anatomy, quantify disease burden using the Lund-Mackay score, and plan surgery if surgery becomes the right answer. A modern low-dose protocol delivers a fraction of the radiation of older scans.
When polyps are present or smell is significantly reduced, additional workup may include allergy testing, peripheral eosinophil count, and screening for aspirin-exacerbated respiratory disease (AERD) — a triad of CRS with polyps, asthma, and aspirin sensitivity that has specific management implications.
Medical first. Surgical when appropriate.
The CRS treatment ladder rises one rung at a time. The vast majority of patients are well-controlled on medical therapy alone. Surgery is the right answer when medical therapy has been given a fair trial and the symptoms persist — not as the default opening move.
Step 1 — Daily medical therapy
The foundation of CRS treatment is daily saline irrigation (high-volume, low-pressure — a sinus rinse, not a spray) combined with a topical intranasal corticosteroid. For polypoid disease, a topical steroid delivered via the irrigation itself (so-called "steroid rinses," off-label but well-established) reaches the sinuses far more effectively than a metered-dose spray. This combination, used consistently for several weeks, resolves or controls a large fraction of CRS cases without anything more invasive.
Step 2 — Targeted antibiotics and short steroid courses
When there is evidence of bacterial infection — purulent discharge confirmed on endoscopy — culture-directed antibiotics are used. Empiric long courses without evidence of infection are avoided because they drive resistance without helping symptoms. Short oral corticosteroid courses are reserved for acute polyp exacerbations or pre-operative shrinkage and are used sparingly because of their systemic side-effect profile.
Step 3 — Surgical intervention
When medical therapy has been adequately tried and symptoms persist — typically defined as continued symptoms after eight to twelve weeks of appropriate management with documented evidence of anatomic obstruction or active inflammation — surgery is the next step. See the next section for what that actually looks like.
Step 4 — Biologic therapy for severe polyp disease
For patients with CRSwNP whose polyps recur after surgery despite adherent topical therapy, biologic medications targeting the underlying Type 2 inflammatory pathway are now standard of care. See below for which biologics, and how candidacy is determined.
Endoscopic, image-guided, and often in-office.
Modern sinus surgery has nothing in common with the procedure your parents may remember. There are no facial incisions. Surgery is performed entirely through the natural openings of the nose using a thin endoscope and dedicated instruments. The goal is not to remove sinus tissue but to open the natural drainage pathways — so that topical therapy, irrigations, and the body's own ciliary clearance can do their job afterward.
Functional endoscopic sinus surgery (FESS)
FESS is the standard surgical approach for CRS. Under endoscopic visualization, the maxillary, ethmoid, frontal, and sphenoid sinus ostia are widened in a precise, anatomy-preserving way. Image-guided navigation — a real-time 3D positioning system referenced to the patient's own CT — is used in every case, so the operating instruments are always located against the patient's specific anatomy rather than against a textbook average.
In-office surgical suites — when appropriate
For a meaningful subset of patients, FESS can be performed in one of two dedicated in-office surgical suites outfitted with the same image-guided navigation, 4K endoscopy, and fluid-management equipment used in the hospital OR. Patient-administered nitrous oxide (Pronox®) provides analgesia and anxiolysis — no IV, no general anesthesia, no hospital booking. Most in-office cases leave the same morning and return to desk work within a week.
In-office surgery is appropriate when the disease is moderate, the anatomy is favorable, and the patient meets medical clearance criteria. It is not appropriate for revision cases with significant scarring, for skull base disease, or for patients on anticoagulation that can't be safely paused. The decision is made together during consultation.
Hospital OR — when complexity warrants it
Complex revision surgery, frontal sinus procedures, cases involving the skull base, and cases requiring a co-surgical neurosurgical team are performed at Mount Sinai. The OR brings advanced visualization — mixed reality with HoloLens, shared OR display, and (for tumor cases) intraoperative fluorescence — to bear on cases that need it.
Recovery, in practical terms
Most patients return to desk work within five to seven days. Saline irrigations begin the day after surgery to keep the surgical bed clean during healing. Follow-up endoscopy at the two-week mark confirms healing is on track, and a second visit at six weeks completes the post-operative course. There is no nasal packing in routine FESS — that practice ended more than a decade ago.
A second front, for the right patients.
For CRS with nasal polyposis driven by Type 2 eosinophilic inflammation, three FDA-approved biologic medications are now available: dupilumab (anti-IL-4Rα), mepolizumab (anti-IL-5), and omalizumab (anti-IgE). These are given by subcutaneous injection — typically every two to four weeks depending on the agent — and target the inflammatory cascade upstream of polyp formation rather than treating the polyps themselves mechanically.
Trial data and real-world experience both show meaningful reductions in polyp burden, return of sense of smell, and reduced need for surgical revision. For patients with severe polypoid disease, comorbid asthma, or AERD — where each individual condition reinforces the others — biologic therapy can be transformative.
Candidacy is determined by polyp grade on endoscopy, symptom severity (using validated tools like the SNOT-22), peripheral eosinophil count, IgE level, comorbid asthma, prior surgery history, and prior medical therapy. Insurance authorization in the United States follows a defined pathway — typically requiring documented failure of intranasal steroids and at least one prior endoscopic surgery — and the practice handles that authorization in-house.
Importantly, biologics and surgery are not alternatives. The most durable outcomes typically combine a well-performed surgery (creating wide drainage pathways for topical therapy and biologic delivery) with appropriate biologic selection and adherent topical maintenance.
When the first surgery didn't fix it.
A meaningful fraction of patients with polyp-predominant CRS will have recurrence within five years of an initial surgery. This is not a failure of the surgery — it is the natural history of the inflammatory disease underneath. The question after recurrence is not "did the surgery work" but "what is the next right step." That answer is patient-specific.
Revision endoscopic surgery, when indicated, addresses anatomy left behind by an incomplete initial procedure, opens drainage pathways that have scarred down, and removes recurrent polyps. Revision cases are technically more demanding because landmarks are altered and tissue planes are scarred — image-guided navigation is essential, and operative time tends to be longer. Outcomes in carefully selected revision cases are excellent.
For patients who have had multiple revisions, the conversation often shifts from "more surgery" to "better medical control" — biologic therapy, AERD-directed desensitization where appropriate, allergy management, and aggressive topical therapy. Surgery becomes a tool to enable medical therapy rather than an end in itself.
Common questions, direct answers.
How do I know if my sinusitis is chronic and not just a long cold?
Chronic rhinosinusitis is defined by symptoms lasting twelve weeks or longer — most commonly nasal congestion, facial pressure, mucopurulent discharge, and reduced sense of smell. A cold typically resolves within ten to fourteen days. Persistent symptoms beyond three months warrant specialist evaluation.
Do I need sinus surgery, or can this be treated medically?
Most chronic rhinosinusitis is treated medically first — daily saline irrigation, intranasal corticosteroids, and targeted antibiotics when an acute infection is present. Surgery is considered when symptoms persist despite an adequate trial of medical therapy, when imaging shows significant anatomic obstruction, or when nasal polyps fail to respond to maximal medical management.
Can sinus surgery be done in the office instead of the hospital?
Yes — for many patients, endoscopic sinus surgery can be performed in a dedicated in-office surgical suite using image-guided navigation, 4K endoscopy, and patient-administered nitrous oxide analgesia. This avoids general anesthesia, eliminates a hospital booking, and most patients return home the same morning. Not every case is appropriate for in-office surgery; the decision is made together during consultation.
What is recovery from endoscopic sinus surgery like?
Most patients return to desk work within five to seven days. Saline irrigations begin the day after surgery to keep the sinuses clean during healing. Bruising and swelling are uncommon because there are no facial incisions — surgery is performed through the natural openings of the nose. Follow-up endoscopy at two weeks confirms that healing is on track.
What is biologic therapy for nasal polyps, and am I a candidate?
Biologic medications — including dupilumab, mepolizumab, and omalizumab — are FDA-approved for chronic rhinosinusitis with nasal polyposis in patients with an eosinophilic inflammatory profile. They are given by subcutaneous injection and reduce polyp burden, restore sense of smell, and lower the chance of repeat surgery. Candidacy is determined by symptom severity, polyp grade, eosinophil markers, and prior treatment history.
I had sinus surgery before and the symptoms came back — what now?
Recurrence after a first endoscopic surgery is common, particularly in polyp-predominant disease. Revision surgery, when indicated, addresses anatomic narrowing left behind, removes recurrent polyps, and creates wider drainage pathways for postoperative irrigations and biologic therapy to reach the sinus mucosa. Image-guided navigation is routinely used in revision cases to safely operate through scarred tissue planes.