A bronchoscopy is used to diagnose a wide range of lung conditions, from cancer and infections to inflammatory diseases and unexplained bleeding. It works by threading a thin, flexible camera through your nose or mouth and into your airways, giving doctors a direct view of your bronchial tubes and the ability to collect tissue or fluid samples. The specific condition your doctor suspects will determine which type of bronchoscopy you need and what sampling techniques are used.
Lung Cancer and Lymph Node Staging
One of the most common reasons for a bronchoscopy is to investigate a suspicious spot on a chest X-ray or CT scan. If a mass or nodule is visible in or near the airways, the doctor can take a tissue sample directly during the procedure. This is often how lung cancer is initially confirmed.
Beyond just identifying cancer, bronchoscopy plays a critical role in determining how far it has spread. A technique called endobronchial ultrasound (EBUS) combines the camera with a small ultrasound probe at the tip, allowing the doctor to see lymph nodes sitting just outside the airway walls and pass a needle through to sample them. In studies of lung cancer patients with suspicious lymph nodes, EBUS achieved a diagnostic accuracy of 96.3%, with a sensitivity of 94.6% and a specificity of 100%. That accuracy significantly outperforms both CT scans and PET scans for lymph node staging, making it a preferred tool before decisions about surgery or other treatment are made.
Lung Infections
When standard tests like blood work or sputum cultures fail to identify a lung infection, bronchoscopy can collect fluid directly from the site of infection. The doctor flushes a small amount of sterile saline into a section of the lung and then suctions it back out, a technique called bronchoalveolar lavage. That fluid is sent to a lab to identify bacteria, fungi, viruses, or parasites.
This approach is especially valuable for people with weakened immune systems, such as organ transplant recipients or those undergoing chemotherapy, who are vulnerable to opportunistic infections that rarely show up on routine tests. It’s also used for community-acquired pneumonia and ventilator-associated pneumonia in hospitalized patients when the standard antibiotic regimen isn’t working and doctors need to pinpoint the exact pathogen. Tuberculosis is another infection frequently diagnosed this way, particularly when sputum samples come back negative.
Sarcoidosis
Sarcoidosis, a condition where clusters of inflammatory cells form in the lungs and lymph nodes, is one of the diagnoses where bronchoscopy is most reliably useful. The characteristic finding is a specific type of tissue clump (a non-caseating granuloma) visible under a microscope.
If the airways look abnormal during the procedure, with a cobblestone-like texture, redness, or small bumps, a simple surface biopsy can confirm the diagnosis in 54% to over 90% of cases. When the airways appear normal, that yield drops to 30% to 40%. For this reason, EBUS-guided needle sampling of enlarged lymph nodes has become the preferred first-line approach. A large meta-analysis found it achieves a diagnostic yield of about 79% overall, rising to 84% at high-volume centers. It still misses the diagnosis in 20% to 40% of cases, particularly in later-stage disease, but it’s far less invasive than surgical biopsy.
Interstitial Lung Diseases
Interstitial lung diseases are a group of conditions that cause scarring or inflammation in the tissue between the air sacs of the lungs. Diagnosing the specific type matters because treatments differ dramatically. Bronchoscopy can help, though its usefulness depends on the technique used and the disease suspected.
Traditional transbronchial biopsies, where small tissue samples are grabbed with forceps through the bronchoscope, work well for certain patterns. They’re particularly effective for organizing pneumonia (where plugs of connective tissue fill the air spaces) and for hypersensitivity pneumonitis, an allergic lung reaction, though the diagnostic yield for the latter is only about 37%. For fibrotic lung diseases like pulmonary fibrosis, these small biopsies reach an accurate diagnosis only 20% to 30% of the time because the tissue samples are simply too small.
A newer technique called cryobiopsy has changed this picture considerably. Instead of forceps, the doctor uses a probe cooled to extremely low temperatures to freeze and extract a larger, better-preserved piece of lung tissue. When reviewed by a team of specialists, cryobiopsy agrees with the gold standard surgical biopsy more than 75% of the time, and up to 95% when the pathology findings are clear-cut. A recent systematic review found an overall tissue yield of 80%, increasing to 85% when three or more samples were taken. Many centers now offer cryobiopsy as an alternative to surgery for patients with undiagnosed interstitial lung disease.
Coughing Up Blood
Bronchoscopy is a go-to tool when someone is coughing up blood (hemoptysis) and the cause isn’t obvious. It serves two purposes at once: finding where the bleeding is coming from and, in many cases, stopping it during the same procedure.
Timing matters. To pinpoint the bleeding site, the doctor needs to see active bleeding, which is most likely during or within 24 to 48 hours of an episode. Bronchoscopy is especially good at detecting problems inside the airways themselves, such as tumors, inflamed tissue, or damaged blood vessels. When combined with a CT scan, it increases the chance of both locating the bleeding and identifying its underlying cause.
Airway Narrowing and Blockages
Bronchoscopy directly visualizes narrowed airways (strictures) or obstructions that may be causing persistent shortness of breath, wheezing, or recurrent infections. These blockages can result from tumors growing into the airway, scar tissue from prior infections or intubation, or inhaled foreign objects.
Most diagnostic bronchoscopies use a flexible scope, which is thin enough to reach deep into the smaller airways and requires only moderate sedation. A rigid bronchoscope, a straight metal tube used under general anesthesia, is reserved for situations involving the larger central airways. It provides better airway control and is preferred when doctors need to deal with significant obstructions from tumors, remove foreign bodies, or place stents to hold a collapsing airway open. In cases of massive bleeding or complex airway problems after lung transplantation, the rigid scope is considered both safer and more effective than the flexible version.
Other Diagnostic Uses
Beyond these major categories, bronchoscopy is used to investigate a persistent cough that hasn’t responded to treatment and has no clear cause on imaging. It can also evaluate vocal cord paralysis, where one or both vocal cords stop moving properly, causing hoarseness or breathing difficulty. In these cases, the scope allows doctors to watch the vocal cords in real time as the patient breathes.
What the Procedure Feels Like
For a flexible bronchoscopy, you’ll receive sedation through an IV to help you relax, and a numbing spray is applied to your mouth and throat (or numbing gel in your nostril if the scope goes through your nose). Most people are awake but drowsy. Rigid bronchoscopy requires general anesthesia, so you’ll be fully asleep.
You won’t be able to eat or drink afterward until your gag reflex returns, because the numbing medicine creates a choking risk if you swallow too soon. You’ll be monitored in a recovery area and typically go home the same day. Overnight stays are rare. Major complications from standard flexible bronchoscopy occur in less than 1% of procedures, and the death rate across large studies is 0.01% to 0.03%. When a transbronchial biopsy is performed, the complication rate is higher at around 6.8%, with bleeding and a small air leak from the lung (pneumothorax) being the main risks.