Bronchiectasis Causes and Risk Factors

Identifying the primary cause of bronchiectasis can be difficult, since different factors lead to injury to the airway walls. 

In the past, childhood infections such as whooping cough and measles caused many U.S. cases of bronchiectasis. However, these infections are now less common, because of vaccines and antibiotics. These days, childhood bronchiectasis is usually caused by cystic fibrosis (CF)primary ciliary dyskinesia (PCD), and certain disorders that weaken the  immune system (the body’s natural defense system). These conditions rarely lead to bronchiectasis among adults.

In adults, disorders that can raise the risk of bronchiectasis include chronic obstructive pulmonary disease (COPD)asthmagastroesophageal reflux disease (GERD), rheumatoid arthritis, and inflammatory bowel disease. Bronchiectasis has also been associated with infections from nontuberculous mycobacteria (NTM) (organisms found in soil, dust, and water). Having bronchiectasis increases the risk for NTM infection, but some individuals have developed bronchiectasis and NTM at the same time.

Bronchiectasis can develop at any age. Half of cases develop after 65 years of age, and most cases worldwide are diagnosed in women. In children, however, the condition is more common in boys than in girls.

How do you get it?

Bronchiectasis can be  congenital  or acquired (developed over time).

  • Congenital bronchiectasis affects infants and children. It results from genetic factors that affect how the lungs form in a fetus.
  • Acquired bronchiectasis occurs as a result of another condition or factor. This type of bronchiectasis can affect adults and older children. Acquired bronchiectasis is more common than the congenital type.

Damage to the walls of the airways — for example, from a more severe lung infection or repeated infections — usually causes acquired bronchiectasis.

Other conditions, such as an airway blockage, also can lead to bronchiectasis. Many things can cause a blockage, such as a growth or a noncancerous tumor. An inhaled object, such as a piece of a toy or a peanut that you inhaled as a child, also can cause an airway blockage.

What raises your risk?

If you have a condition that damages your lungs or increases the risk of lung infections, you may have a higher risk of bronchiectasis. Examples of such conditions include:

  • Cystic fibrosis, which causes almost half of the cases of bronchiectasis in the United States
  • Disorders that weaken theimmune system, such as common variable immunodeficiency (CVID) and, less often, HIV
  • Allergic bronchopulmonary aspergillosis, which is an allergic reaction to a  fungus  called aspergillus that causes swelling in the airways
  • Disorders that affect cilia function, such as primary ciliary dyskinesia, can cause bronchiectasis. Cilia are small, hairlike structures that line your airways. They help clear  mucus  (a thick, slippery fluid) out of your airways.
  • Chronic (long-term) pulmonary aspiration, a condition where inhaled substances such as digestive fluids or small food particles get into the lungs and inflame the airways
  • Connective tissue diseases, such as rheumatoid arthritis, Sjögren’s syndrome, and Crohn’s disease 

Can you prevent bronchiectasis?

To prevent bronchiectasis, it’s important to prevent lung infections and lung damage.

  • Get childhood vaccines for measles and whooping cough. These vaccines also reduce complications from these infections, such as bronchiectasis.
  • Get pneumonia, influenza, and COVID-19 vaccines to lower the chance of these infections affecting the lungs. 
  • Avoid toxic fumes, gases, smoke, and other harmful substances to help protect your lungs.
  • Treat lung infections in children to help preserve lung function and prevent lung damage that can lead to bronchiectasis.
  • Stay alert to keep children and adults from inhaling small objects such as pieces of toys and food that might stick in a small airway. If you think you, your child, or someone else has inhaled a small object, seek medical care right away.

In some cases, treating the basic cause of bronchiectasis can slow or prevent its progression.

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