Bronchiectasis is caused by two phases of airway damage. In the first phase, the initial damage (or “insult”) is caused by an infection, inflammatory disorder or another condition that affects your lungs. Healthcare providers don’t know the initial cause in up to 40% of people with bronchiectasis. The first insult makes you more likely to get inflammation and repeated infections that cause further damage to your lungs. This is the second phase, or the “vicious cycle.”