Nasal Endoscopy Explained: What to Expect During the Procedure

Why a scope, when the nose is right there

The part of the nose that causes most trouble is the part you cannot see from the front. A head-light and a nasal speculum give a reasonable view of the septum, the front of the inferior turbinate and the nasal vestibule — and that is genuinely useful, since a deviated septum or a swollen front turbinate explains a great many blocked noses. But the sinuses do not open at the front. They drain through narrow channels several centimetres back, in a region called the middle meatus, tucked under the middle turbinate.

A nasal endoscope is a thin telescope, roughly the width of a thick pen refill in adults and considerably thinner in children, that carries a light source and a lens to that area. The image appears on a monitor at magnification, so mucosal swelling, a strand of pus, a small polyp or an area of crusting are seen directly rather than inferred.

It is an examination, not an intervention

It is worth separating two things that share a name. Diagnostic nasal endoscopy is what this article describes: an outpatient look, performed awake, taking a few minutes. Endoscopic sinus surgery uses the same optical principle but is an operation performed under anaesthesia in a theatre — at an attached hospital, not at the Golf City clinic — and is a separate decision made only after medical treatment has been given a fair trial.

Which leads to the more useful question: once the scope is in, what is actually being looked for?

What the view actually shows

Endoscopy is looking for a small number of specific findings, not browsing. In chronic rhinosinusitis, the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS 2020) defines the condition as the right combination of symptoms lasting long enough, plus either endoscopic signs or CT changes. The endoscopic signs it names are narrow and concrete: nasal polyps, mucopurulent discharge coming primarily from the middle meatus, or oedema and mucosal obstruction primarily in the middle meatus.

That structure matters for a patient, because it explains why an ENT may seem uninterested in a long description of symptoms alone. Symptoms establish the possibility; the examination is what confirms or removes it. The 2025 update of the AAO-HNSF adult sinusitis guideline makes the same point from the other direction, recommending that a clinical diagnosis of chronic rhinosinusitis be confirmed with objective documentation of sinonasal inflammation — by anterior rhinoscopy, nasal endoscopy or CT.

Beyond the sinus question

• Structural causes of blockage — septal deviation and spurs further back than a speculum reaches, turbinate enlargement, adhesions from previous surgery or injury, a septal perforation.
• The nasopharynx — the space behind the nose, including the adenoid pad and the Eustachian tube openings, which is relevant to persistent ear blockage and to mouth breathing in children.
• A bleeding point — in recurrent nosebleeds, a vessel too far back for a front-of-nose examination to find.
• Anything one-sided — a mass, unusual crusting or a polyp confined to one side, which is treated as a finding needing explanation rather than reassurance.

Key limitation: endoscopy shows the surfaces the scope can reach. It does not see inside the maxillary or frontal sinus cavities, cannot measure how much disease sits within them, and does not by itself distinguish a benign polyp from a growth that needs tissue diagnosis. A normal endoscopy also does not rule out every cause of a blocked nose — non-allergic rhinitis, medication overuse and some structural problems can coexist with an unremarkable view.

When it changes the plan — and when it doesn't

The honest answer is that many people with nasal symptoms never need a scope. A first episode of acute sinusitis, a clear seasonal allergy pattern, a simple viral cold — none of these are endoscopy questions, and a course of appropriate treatment answers them faster than a camera does. Endoscopy earns its place when the answer will change what happens next.

The situations where it usually does

• Symptoms lasting beyond about twelve weeks despite reasonable treatment, where a diagnosis of chronic rhinosinusitis needs to be confirmed rather than assumed.
• Suspected nasal polyps, where confirming their presence or absence changes both the medical plan and the discussion about surgery.
• Persistent one-sided symptoms of any kind — this is the strongest single indication, and the reason is covered further down.
• Recurrent nosebleeds where the source has not been identified at the front of the nose.
• Persistent smell loss that has not recovered, where the olfactory cleft needs to be inspected.
• Blockage that has not responded to a properly used nasal steroid spray, where the question becomes whether the obstruction is inflammatory or structural.
• Persistent ear fullness or one-sided fluid behind the eardrum in an adult, where the nasopharynx needs to be seen.

Equally, there are times to say no. Endoscopy in the middle of an acute infection is often uninformative and more uncomfortable than usual, and is generally better deferred unless there is concern about a complication. And a scope done because it is available, rather than because a question needs answering, adds cost and discomfort without adding clarity. That said, the most common reason patients decline is not cost — it is the expectation that it will hurt.

What actually happens, step by step

The whole thing is shorter than the consultation that precedes it. You sit upright in the examination chair, head supported, and the sequence runs roughly as follows.

1. The conversation and consent

The clinician explains what is about to happen and asks about anything that changes the approach: previous nose surgery, a known bleeding tendency or blood-thinning medication, recent nasal trauma, or a very narrow nose. Verbal consent is standard for this kind of outpatient examination.

2. Preparing the nose

A decongestant spray, sometimes combined with a local anaesthetic, may be used to shrink the lining and widen the passage. It takes a few minutes to work and tastes bitter as it trickles backwards. This step is optional rather than automatic, for reasons explained in the next section, and you should be asked which side of your nose feels more open.

3. The examination

The scope is lubricated and passed gently along the floor of the nose, then withdrawn and passed along a higher route, so that the different levels of the nasal cavity are inspected in turn. If the nasopharynx and larynx also need to be seen, the scope continues past the back of the nose and you may be asked to sniff, swallow, poke your tongue out or say "eeee" — each of these opens up an area that is otherwise hidden. You can breathe normally throughout; the scope occupies a small part of one nostril, not your airway.

4. Finishing

Both sides are usually examined unless one is clearly the problem. Images are captured for the record so that the appearance can be compared at a future visit. Total scope time is typically two to five minutes.

Nothing in that sequence involves cutting or injections. The part patients dread is the passing of the scope itself — which turns out to be the part the evidence has most to say about.

Does it hurt? What the evidence says about numbing spray

Most people find it strange rather than painful. The usual descriptions are a pressure sensation, a tickle that makes the eyes water, and an urge to sneeze — all lasting seconds. Discomfort is greater in a very narrow or very inflamed nose, and greater still if the scope is forced, which is why an unhurried technique matters more than any spray.

The spray question is genuinely interesting, because the intuitive answer is wrong. A Cochrane review of topical preparations before flexible nasal endoscopy found no clear evidence that they reduce pain or discomfort, and noted that some authors argue against routine use because of cost and unpleasant side effects. A separate systematic review and meta-analysis of eight randomised trials in 818 patients reached a similar conclusion: no difference in pain scores between local anaesthetic, vasoconstrictor and lubricating agents, with co-phenylcaine associated with greater taste unpleasantness and lidocaine, in one trial, with more pain. Both reviews are cautious about their own conclusions, since several of the underlying trials were small.

What that means in practice

It does not mean sprays are useless. A decongestant can widen a genuinely narrow passage and improve the view, and a single trial in that meta-analysis did find lower overall unpleasantness with xylometazoline. It does mean that being sprayed is not the thing standing between you and a comfortable examination, and that declining the anaesthetic — or being told it is not needed — is a defensible clinical position rather than a shortcut.

Complications are uncommon. The recognised ones are sneezing, a small amount of bleeding from mucosal contact, gagging when the scope passes further back, and occasionally light-headedness. A brief nosebleed is the one people notice, and adequate decongestion and gentle technique are what prevent it.

Nasal endoscopy in children

Children tolerate it better than most parents expect, but the decision is more finely balanced than in adults. Paediatric scopes are considerably thinner — down to around 2 mm — and in a cooperative, prepared child the examination is brief. In a distressed toddler it is neither kind nor informative, and there is no merit in forcing it.

The commonest reason to consider it is the adenoid. A child with persistent mouth breathing, snoring, a permanently blocked nose or recurrent ear fluid is often being assessed for adenoid enlargement, and endoscopy gives a direct view of the pad and how much of the airway it occupies — where a lateral X-ray gives a two-dimensional shadow and clinical examination alone is unreliable. Endoscopy is generally regarded as the reference standard for this assessment, with radiography as a practical alternative when a child cannot cooperate.

What makes it go well

• Explaining honestly beforehand: it feels strange, it is quick, it does not involve a needle.
• The child sitting on a parent's lap for younger ages, with gentle head support.
• Accepting a partial examination. A brief look at the nasopharynx often answers the question; a complete survey is not always necessary.
• Stopping if the child is genuinely distressed and reconsidering, rather than persisting.

If you are weighing this up for a child, the clinic's guides on persistent mouth breathing in children and when a child should see an ENT cover the surrounding decisions. What happens after the scope, for adults and children alike, is usually the part that gets least explanation.

Afterwards, and reading your report

There is no recovery period to speak of. Nothing sedating is given for a routine diagnostic examination, so driving, working and eating are unaffected — the exception being that if a local anaesthetic spray was used and your throat feels numb, it is sensible to wait around an hour before eating or drinking so you do not scald or choke yourself without noticing. Sneezing and eye-watering settle within minutes. A small amount of blood-tinged mucus for a nose-blow or two is common and not a cause for concern; bleeding that continues beyond a few minutes is worth reporting.

What a useful report contains

Findings are more helpful when they are specific. A report or a verbal explanation should tell you which side, which structure, and what the appearance means for the plan — not simply "endoscopy done, sinusitis present". Reasonable things to ask before you leave:

• What did you see, and on which side?
• Does it explain my main symptom, or only part of it?
• Has anything been ruled out by this examination — and what has not?
• Does this change the treatment, or confirm the treatment I am already on?
• Do I need any further test, and what question would that test answer?

That last question is the one that keeps investigations proportionate, because endoscopy sits alongside other tests rather than replacing them.

What endoscopy does not replace

Endoscopy and CT agree more often than patients assume. A systematic review of sixteen studies cited in EPOS 2020 reported a high correlation between endoscopy and paranasal sinus CT for the diagnosis of chronic rhinosinusitis (r = 0.85, 95% CI 0.78–0.94), which is part of why guidelines accept either as objective confirmation. Agreement is not equivalence, though, and the two answer different questions.

Where allergy is the driver, the nose may look inflamed on the scope without endoscopy telling you what it is reacting to. Skin prick testing answers a different part of the question, and for confirmed allergic rhinitis sublingual immunotherapy is a longer-term option matched to those results. If sinus symptoms and allergy symptoms have blurred together, the guide on seasonal allergies versus sinusitis is the better starting point.

Clinical sources

1. European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020. Rhinology, supplement 29.
2. Clinical Practice Guideline: Adult Sinusitis (Update). American Academy of Otolaryngology–Head and Neck Surgery Foundation, Otolaryngology–Head and Neck Surgery.
3. Alvi S, Harsha P. Flexible Nasopharyngoscopy. StatPearls, StatPearls Publishing, updated 2023.