When you have bronchiectasis, your airways (bronchial tubes) are damaged.
Bronchiectasis damages the tiny hairs (cilia) that line the inside of your airways. Damaged cilia can't do their job of sweeping dirt and mucus out of your lungs. With bronchiectasis, your airways widen and stretch out. In some places the airways are so stretched out they form little pockets. Germs, dust and mucus collect in these pockets and get stuck.
After a while the germs, dust and mucus that are stuck in your airways get infected. Your tiny hairs (cilia) can't sweep them away, so the infections keep coming back. Bronchiectasis creates a vicious cycle; infections in airway pockets damage your airways, and when your airways are damaged, you get more infections.
Bronchiectasis can’t be cured, but with the right treatment, most people with bronchiectasis can live relatively normal lives.
Bronchiectasis can be caused by many things: