How Bronchiectasis Is Diagnosed

Understanding How Bronchiectasis is Diagnosed

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Bronchiectasis is among a group of lung disorders classified as chronic obstructive pulmonary disease (COPD). A diagnosis of bronchiectasis is sometimes difficult to make, as bronchiectasis symptoms are often mistaken for other lung disorders, such as emphysema, pneumonia, or lung cancer.

Specific tests, such as pulmonary function tests, chest X-rays, and sputum cultures can all help narrow down a diagnosis of bronchiectasis.


Because the symptoms of bronchiectasis are so similar to numerous other lung conditions, such as bronchitis or asthma, this condition cannot be diagnosed based on self-checks.

That said, it's important to pay attention to the signs and symptoms, and to describe them to your doctor as soon as possible to prevent further damage.

Seek professional care promptly if you notice:

  • A chronic cough with thick mucus that's difficult to clear
  • Wheezing
  • Fatigue
  • Weakness
  • Clubbing of the fingers

Labs and Tests

The first thing that your doctor is likely to do is take a thorough history and perform a physical examination. This includes asking questions about your health history and exposures to airway irritants, such as cigarette smoke, air pollution and chemicals in the workplace.

A head-to-toe physical assessment will include listening to your lungs with a stethoscope and examining your chest wall for abnormalities. After these exams, if your doctor still suspects a diagnosis of bronchiectasis, the following tests may be ordered to confirm it.

Pulmonary Function Test

Pulmonary function tests help your medical team assess your lung function by measuring how efficiently air flows. This can determine the amount of lung damage present.

There are several types of pulmonary function tests that can be helpful in making a diagnosis of bronchiectasis and other types of COPD, including:

  • Spirometry, a noninvasive test that measures lung function as you breathe through a tube
  • Lung diffusion studies, another noninvasive test that determines how much carbon monoxide you inhale versus exhale to help assess how efficiently your lungs are performing
  • Lung plethysmography, a test that looks at your total lung capacity, or the amount of air you're able to take in as breath and how much is left over after you exhale (known as functional residual volume)

Sputum Culture

People with bronchiectasis are prone to frequent lung infections. A sputum culture is a lab test that analyzes a small amount of sputum (mucus) in an agar dish (growing medium) to look for bacterial growth. The test helps identify the specific bacteria strain(s) in the mucus, which can lead to more efficient treatment with the type of antibiotic that is most likely to target the bacteria.


Imaging tests are also common methods used in the diagnosis of bronchiectasis.

Chest X-Ray

This noninvasive imaging technique uses electromagnetic waves to create a picture of your lungs and diaphragm. X-rays are performed in some doctors' offices, medical imaging centers, and hospitals.

Generally speaking, abnormalities in the lungs due to COPD do not show up until the damage is severe. So, while a chest X-ray does not provide a definitive diagnosis of bronchiectasis or other forms of COPD, it does help support one.

Chest CT Scan

A chest CT is often used as part of the diagnosis of bronchiectasis, and your doctor may also order a chest CT if you've had a change in symptoms, an infection is not resolving, or you are getting ready for surgery.

A chest CT provides a more detailed image than an X-ray, as it takes numerous cross-sectional pictures (slices) of your lungs and chest and combines them to form a 3D (rather than a 1D) image.

The test is usually performed in a medical imaging center or a hospital.

Differential Diagnoses

Before reaching a diagnosis of bronchiectasis, your doctor may also test you for associated conditions, such as cystic fibrosis or tuberculosis. This will help rule out or confirm a diagnosis of bronchiectasis.

Other conditions your doctor will look into include:

  • Infection: Pneumonia or bronchitis could result in similar symptoms to bronchiectasis.
  • Cystic fibrosis: This genetic condition affects the lungs and other organs and may result in increased mucus secretions.
  • Tuberculosis: Bronchiectasis may occur in conjunction with or be caused by tuberculosis, a disease caused by bacteria that usually attacks the lungs. Your doctor will perform specific lab work to rule out this disease.
  • Immune conditions: Autoimmune conditions such as asthma or an immune deficiency such as alpha1-antitrypsin (AAT) deficiency can produce symptoms similar to those of bronchiectasis.

A Word From Verywell

While bronchiectasis can take time to diagnose, there are several diagnostic tests that can help clarify the situation. Several therapies have been shown to be beneficial, and lifestyle modifications can also help. The most important thing is to seek treatment quickly to prevent further damage to the lungs and to identify your best treatment plan.

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