Bronchoscopy and Bronchoalveolar Lavage (BAL)

Why this test may be ordered

• To find the cause of lung symptoms like a persistent cough, trouble breathing, or coughing up blood
• To diagnose lung infections such as tuberculosis, bacterial pneumonia, or fungal infections
• To diagnose lung cancer or determine its severity
• To remove blockages, tumors, or control bleeding in the airways

Preparation and collection

You may need to fast (not eat or drink) for several hours before the procedure. Your provider will tell you how long. Also, you may need to stop taking certain medicines; do not stop unless your provider tells you to.

You will lie down with your head raised. You may receive a sedative through an IV. A numbing spray will be applied to your mouth and throat. The bronchoscope is inserted through your mouth or nose into your airways. For BAL, a small amount of saline is used to wash the airways and then collected for testing.

There is very little risk to having a bronchoscopy or a BAL. Serious complications are rare, but they may include bleeding in the airways, infection, or a pneumothorax (collapse of part of your lung).

Understanding results

Your healthcare provider will review the images from the bronchoscopy and the results from the BAL fluid sample. The following are possible result patterns. Your provider will interpret them along with your symptoms, medical history, and other tests.

• Bronchoscopy: Normal appearance of airways: No visible blockages, growths, or narrowing were seen. Limitation: May not detect microscopic abnormalities or early disease. Next step: No further action based on this result alone; your provider will consider other tests.
• Bronchoscopy: Abnormal findings (e.g., blockage, tumor, narrowing): May indicate a lung disorder such as a growth, tumor, or narrowing of the airways. Limitation: Cannot confirm diagnosis; biopsy or further testing is needed. Next step: Your provider may recommend a biopsy or additional imaging to determine the cause.
• BAL fluid: No infection or cancer cells detected: No evidence of lung infection or cancer in the sample. Limitation: False negatives are possible; may not detect all infections or early cancer. Next step: Your provider will consider your symptoms and other test results.
• BAL fluid: Infection or cancer cells detected: May indicate a lung infection (e.g., tuberculosis, bacterial pneumonia, fungal infection) or lung cancer. Limitation: Further testing may be needed to identify the specific infection or cancer type. Next step: Your provider will discuss treatment options based on the specific diagnosis.

• Results from bronchoscopy and BAL are not diagnostic on their own; they must be interpreted along with your symptoms, medical history, and other tests.
• There is a small risk of false negatives; a normal result does not completely rule out disease.
• The procedure carries rare but serious risks such as bleeding, infection, or lung collapse.

What to do next

Your healthcare provider will review your results along with your symptoms, medical history, and any other tests to make a diagnosis. Follow up with your provider to discuss what your results mean for you.

• What do my results mean for my health?
• Do I need any follow-up tests or procedures?
• What are the next steps in my treatment?
• Are there any symptoms I should watch for after the procedure?
• How will my results affect my treatment plan?

Evidence source

U.S. National Library of Medicine: Bronchoscopy and Bronchoalveolar Lavage (BAL)