Is a concha bullosa serious?

No. It is a normal anatomical variant present in roughly a third of people. It becomes clinically relevant only when it is large enough to obstruct the nasal airway or the sinus drainage path, and even then it is treated on symptoms rather than on the scan.

Does it cause sinus infections?

It can contribute, by narrowing the channel the sinuses drain through, but the evidence is mixed and most people with one never have sinus trouble. It is one factor among several rather than a cause on its own.

Only if it is genuinely obstructing and causing symptoms that have not responded to medical treatment. If it was an incidental finding on a scan done for something else and your breathing is fine, no.

Is it related to my deviated septum?

They are strongly associated: a large concha bullosa on one side commonly accompanies a septum deviated to the other. The two develop in relation to one another, and a surgeon treating one will usually assess both.

It is a developmental variant rather than a progressive condition, so it does not grow in adults. It does not need monitoring.

Findings explained

What “concha bullosa” means on a sinus CT

Read Your Scan Editorial Team·Last updated 10 September 2026·5 min read

Written from published radiology references and reviewed for plain language. Not written or signed by a physician, and not a diagnosis. How we write these pages →

Coronal CT of the ostiomeatal complex and paranasal sinuses — A real coronal CT through the sinuses — the exact view this finding is described on. The turbinates are the scroll-shaped structures projecting into the nasal cavity from each side wall, and a concha bullosa is a dark air pocket inside one of them.Real exam · Mikael Häggström, M.D. · CC BY 4.0

The short answer

A concha bullosa is an air-filled cavity inside one of the turbinates — the scroll-shaped structures on the side wall of the nose. It is a normal anatomical variant, not a disease, and it is found in roughly a third of people scanned. Most cause nothing at all. A large one can narrow the nasal airway or the drainage path from the sinuses, and only then does it become clinically relevant.

It is a normal variant, not an abnormality. Around a third of people have one.
A turbinate is normally solid bone covered in lining; here it has pneumatised — developed an air cell inside.
It is strongly associated with the septum being deviated towards the opposite side.
Most are silent. Size is what decides whether it does anything.
It is treated only when it is genuinely obstructing, and the operation to do so is minor.

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What a turbinate is

The inside of your nose is not an empty tube. Projecting from each side wall are three curled shelves of bone covered in lining, called turbinates or conchae. They exist to slow air down, warm it, humidify it and filter it — they turn a straight passage into something with a great deal more surface area.

They are normally solid bone under that lining. In a concha bullosa, the middle turbinate has instead developed an air cell inside it, connected to the sinus air spaces. The bone is hollow rather than solid.

The Latin is literal: concha for the shell-like shape, bullosa from bulla, a bubble. A bubble in the shell.

How common, and why it is a variant

Studies of sinus CT scans put the rate at around a third of people, with ranges across studies from roughly one in seven to more than half depending on how strictly it is defined. It is frequently on both sides.

That prevalence is why radiologists file it as a normal variant rather than an abnormality. It is a way noses are built, not a thing that has gone wrong, and describing it in a report is the same kind of statement as describing which way someone’s septum leans.

Axial CT of a normal brain — A standard axial head CT. Concha bullosa turns up on scans like this one too — ordered for headaches, dizziness or after an injury — which is why so many people meet the phrase without ever having had a sinus problem.Real exam · Mikael Häggström, M.D. · CC0 1.0

The connection with a deviated septum

There is a consistent association: a large concha bullosa on one side tends to accompany a septum deviated towards the other side.

The usual explanation is developmental. As the structures of the nose grow, a turbinate expanding on one side and a septum leaning away from it accommodate one another in the fixed space available. Which one leads is not settled.

Practically, it means your report may well mention both, and that a surgeon considering treating one will look at the other.

When it actually matters

When it is big enough to take up space that is needed. Two things can be affected:

The nasal airway. A large concha bullosa can narrow the passage on that side and contribute to a blocked nose, usually one-sided.
The drainage path from the sinuses. The turbinate sits beside the narrow channel the sinuses drain through, and a big air cell can obstruct it — which is the mechanism linking concha bullosa to recurrent sinus infections.

The evidence that concha bullosa causes sinusitis is mixed, precisely because so many people have one and never get sinus trouble. Radiologists therefore report it and leave the significance to the clinical picture.

Rarely, the air cell itself becomes obstructed and fills with fluid or infected material. That is a specific situation and the report will describe it as such rather than simply naming the variant.

What usually happens next

For the great majority: nothing. It is noted, and it does not need treating, watching or re-scanning.

If there is persistent one-sided blockage or recurrent sinus problems, and an ENT surgeon assesses that this is contributing, the operation is minor: part of the turbinate is removed or the air cell is collapsed, usually endoscopically through the nostril and often alongside straightening the septum.

The decision is made on symptoms and examination, not on the scan alone. A concha bullosa on a report in someone who breathes fine through both nostrils is not a reason to operate.

Frequently asked questions

Is a concha bullosa serious?: No. It is a normal anatomical variant present in roughly a third of people. It becomes clinically relevant only when it is large enough to obstruct the nasal airway or the sinus drainage path, and even then it is treated on symptoms rather than on the scan.
Does it cause sinus infections?: It can contribute, by narrowing the channel the sinuses drain through, but the evidence is mixed and most people with one never have sinus trouble. It is one factor among several rather than a cause on its own.
Do I need surgery?: Only if it is genuinely obstructing and causing symptoms that have not responded to medical treatment. If it was an incidental finding on a scan done for something else and your breathing is fine, no.
Is it related to my deviated septum?: They are strongly associated: a large concha bullosa on one side commonly accompanies a septum deviated to the other. The two develop in relation to one another, and a surgeon treating one will usually assess both.
Will it get bigger?: It is a developmental variant rather than a progressive condition, so it does not grow in adults. It does not need monitoring.

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Sources

Patient-facing procedure descriptions (MRI, CT, X-ray, ultrasound)RadiologyInfo.org — Radiological Society of North America & American College of Radiology
CT scan — overview, how it is performed and resultsNHS (United Kingdom)
ACR Appropriateness Criteria and practice parameters for reportingAmerican College of Radiology

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Read Your Scan is informational only — not a medical diagnosis, and not a substitute for a licensed radiologist or your doctor. This page explains what a report says and what a radiologist looks at; it cannot tell you what your own images show. If you have urgent symptoms, seek care.