Bronchiectasis Causes and Risk Factors

---

In the United States, childhood infections such as whooping cough and measles used to cause many cases of bronchiectasis. However, these infections are now less common because of vaccines and antibiotics.

These days, bronchiectasis usually is caused by medical conditions such as cystic fibrosis and primary ciliary dyskinesia, that injure the airway walls or prevent the airways from clearing mucus.

Bronchiectasis can develop at any age. Overall, two-thirds of people who have the condition are women. However, in children, the condition is more common in boys than in girls.

Bronchiectasis can be congenitalor acquired.

• Congenital bronchiectasis affects infants and children. It's the result of a problem with 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 lung infection – usually causes acquired bronchiectasis. Examples of lung infections that can lead to bronchiectasis include:

• Severe pneumonia  
• Whooping cough or measles (uncommon in the United States due to vaccination)
• Tuberculosis
• Fungal infections

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?

People who have conditions that damage the lungs or increase the risk of lung infections are at risk of bronchiectasis. Examples of such conditions include:

• Cystic fibrosis, which causes almost half of the cases of bronchiectasis in the United States
• Immunodeficiency disorders, such as common variable immunodeficiency and, less often, HIV and AIDS
• 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, hair-like structures that line your airways. They help clear mucus (a slimy substance) out of your airways.
• Chronic (long-term) pulmonary aspiration, which can 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 the lung infections and lung damage that can cause it.

• Get childhood vaccines for measles and whooping cough. These vaccines also reduce complications from these infections, such as bronchiectasis.
• 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.