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Bronchoscopy and Bronchoalveolar Lavage (BAL)

What are bronchoscopy and bronchoalveolar lavage (BAL)?

Bronchoscopy is a procedure that allows a health care provider to look at your lungs. It uses a thin, lighted tube called a bronchoscope. The tube is put through the mouth or nose and moved down the throat and into the airways. It helps diagnose and treat certain lung diseases.

Bronchoalveolar lavage (BAL) is a procedure that is sometimes done during a bronchoscopy. It is also called bronchoalveolar washing. BAL is used to collect a sample from the lungs for testing. During the procedure, a saline solution is put through the bronchoscope to wash the airways and capture a fluid sample.

Other names: flexible bronchoscopy, bronchoalveolar washing

What are they used for?

Bronchoscopy may be used to:

  • Find and treat growths or other blockages in the airways
  • Remove lung tumors
  • Control bleeding in the airway
  • Help find the cause of persistent cough

If you've already been diagnosed with lung cancer, the test can help show how severe it is.

Bronchoscopy with BAL is used to collect tissue for testing. These tests help diagnose different disorders of the lungs including:

One or both tests may be used if an imaging test showed a potential problem with the lungs.

Why do I need bronchoscopy and BAL?

You may need one or both tests if you have symptoms of a lung disease, such as:

You may also need a BAL if you have an immune system disorder. Some immune system disorders, such as HIV/AIDS, can put you at higher risk for certain lung infections.

What happens during bronchoscopy and BAL?

Bronchoscopy and BAL are often done by a pulmonologist. A pulmonologist is a doctor who specializes in diagnosing and treating lung diseases.

A bronchoscopy usually includes the following steps:

  • You may need to remove some or all of your clothing. If so, you will be given a hospital gown.
  • You will recline in a chair that is like a dentist's chair or sit on a procedure table with your head raised.
  • You may get medicine (sedative) to help you relax. The medicine will be injected into a vein or given through an IV (intravenous) line that will be placed in your arm or hand.
  • Your provider will spray a numbing medicine in your mouth and throat, so you won't feel any pain during the procedure.
  • Your provider will insert the bronchoscope down your throat and into your airways.
  • As the bronchoscope is moved down, your provider will examine your lungs.
  • Your provider may perform other treatments at this time, such as removing a tumor or clearing a blockage.
  • At this point, you may also get a BAL.

During a BAL:

  • Your provider will put a small amount of saline through the bronchoscope.
  • After washing the airways, the saline is sucked up into the bronchoscope.
  • The saline solution will contain cells and other substances, such as bacteria, which will be taken to a lab for testing.

Will I need to do anything to prepare for the test?

You may need to fast (not eat or drink) for several hours before your procedure. Your provider will let you know how long you need to avoid food and drink.

You should also arrange to have someone drive you home. If you've been given a sedative, you may be drowsy for a few hours after your procedure.

Are there any risks to the test?

There is very little risk to having a bronchoscopy or a BAL. The procedures may give you a sore throat for a few days. Serious complications are rare, but they may include bleeding in the airways, infection, or a collapsed part of a lung.

What do the results mean?

If your bronchoscopy results were not normal, it may mean you have a lung disorder such as:

  • A blockage, growth, or tumor in the airways
  • Narrowing of part of the airways
  • Lung damage due to an immune disorder such as rheumatoid arthritis

If you had BAL and your lung sample results were not normal, it may mean you have lung cancer or a type of infection such as:

  • Tuberculosis
  • Bacterial pneumonia
  • Fungal infection

If you have questions about your results, talk to your health care provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about bronchoscopy and BAL?

In addition to BAL, there are other procedures that can be done during a bronchoscopy. These include:

  • Sputum culture. Sputum is a thick type of mucus made in your lungs. It is different than spit or saliva. A sputum culture checks for certain types of infections.
  • Laser therapy or radiation to treat tumors or cancer
  • Treatment to control bleeding in the lungs


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The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.