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Diagnosing Bronchiectasis

At NYU Langone, our pulmonary specialists have extensive experience in diagnosing and managing bronchiectasis, a lung condition that causes scarring and widening in the airways. 

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The lungs contain tubes called bronchi, which branch into thousands of smaller tubes called bronchioles. Mucus, also called sputum, coats the lining of these tubes to keep them moist and trap any foreign particles that enter the lungs. Tiny hairs called cilia, which line the airways, are responsible for sweeping excess mucus out of the lungs so it can be coughed up and expelled from the body. 

In bronchiectasis, the walls of the airways become thick and dilated, making it hard to move mucus out. As a result, mucus builds up in the airways, allowing bacteria to flourish and increasing the risk of severe infections. People with bronchiectasis frequently experience a cough, usually with sputum, and may experience shortness of breath. 

There are several possible causes of bronchiectasis. One is cystic fibrosis, an inherited condition that leads to thick mucus in the lungs and sinuses that is difficult to clear. 

Having an immunoglobulin deficiency—in which a person lacks an antibody that protects against infection of the mucus membranes that line the mouth, nose, and airways—also puts you at risk. An immunoglobulin deficiency can come on spontaneously or can be passed down in families.

Many people develop bronchiectasis when a serious infection, such as tuberculosis, whooping cough, or pneumonia, injures the walls of the airways. The condition may also occur in conjunction with an autoimmune condition, such as rheumatoid arthritis or Sjogren’s syndrome. These conditions affect the joints and connective tissues, causing inflammation throughout the body, including the lungs. 

Chronic gastroesophageal reflux disease, also known as GERD, can trigger symptoms of bronchiectasis. When stomach acid travels back up into the esophagus, acid may enter the lungs, irritating them.

To diagnose bronchiectasis, an NYU Langone pulmonologist first takes a medical history. He or she asks whether you have any conditions associated with bronchiectasis, such as rheumatoid arthritis, or if you had severe lung infections as a child. Your doctor may also recommend the following tests. 

Chest X-ray

A chest X-ray uses electromagnetic radiation to create pictures of structures in the chest, such as your heart and lungs. It can detect lung scarring, a sign of bronchiectasis, and it can help rule out other pulmonary conditions.

CT Scan

If a chest X-ray doesn’t provide enough detail, your pulmonologist may order a CT scan, which uses X-rays and a computer to create three-dimensional, cross-sectional images of the body. A CT scan may reveal dilated, thickened airways, which are commonly found in bronchiectasis.

Sputum Culture 

Your pulmonologist may want to test your sputum, or mucus, for bacteria to determine whether you have a lung infection. He or she collects a sample of coughed-up phlegm and sends it to the lab for examination. If any uncommon bacteria are found, your doctor may suspect bronchiectasis. 

For people diagnosed with bronchiectasis, a pulmonologist may recommend regular sputum testing to look for certain types of infections, such as fungal or atypical mycobacterial infections.

Pulmonary Function Test

A pulmonary function test is a group of tests used to assess lung function and possible damage. The tests measure the amount of air your lungs can hold, how quickly air is inhaled and exhaled, and how much oxygen is delivered to the blood through the lungs. 

The most commonly used test is called spirometry. It measures how much and how quickly you can move air out of your lungs. During this test, you breathe into a mouthpiece attached to a recording device, or spirometer. People with lung damage tend to have trouble exhaling.


If you have bronchiectasis and are not responding to treatment, your pulmonologist may want to perform a bronchoscopy to get a better look at your lungs for further evaluation. A bronchoscope—a long, thin, flexible tube with a light attached to it—is inserted through the nose or mouth and into the airways. 

Using a video monitor that serves as a guide, the doctor leads the bronchoscope through the airways to look for a blockage due to excess, thick mucus. Most people receive sedation for the procedure and can return home the same day.

Our Research and Education in Bronchiectasis

Learn more about our research and professional education opportunities.