What is Bronchiectasis?
Bronchiectasis is the abnormal, permanent dilation of the upper airways of the lungs. The branches of airways, called bronchi, become progressively smaller until they reach the alveoli, which are numerous small sacks or air where the exchange of oxygen and carbon dioxide take place. Bronchiectasis only affects the elasticity of the smooth muscle and cellular wall of the larger upper airways.
This results in greater difficulty effectively clearing secretions from the lungs, which in turn leads to greater frequency of infection. This begins a cycle of further damage, inflammation, greater mucus production and retention, ultimately leading to more infections. Even the body’s own immune response can, under these conditions, add to the damage of the airways.
What causes Bronchiectasis?
There are numerous causes for bronchiectasis. However, in approximately 50% of cases, an underlying cause is not found.
Bronchiectasis may present as a primary lung manifestation of lung conditions, which can cause chronic inflammation resulting from an abnormality of anatomy, immunity or function.
These conditions include:
- Post infections such as pneumonia, tuberculosis, measles, influenza and whooping cough
- Immune Deficiency such as lung and bone marrow transplant. Malignancy and HIV/AIDS
- Cystic Fibrosis
- Pulmnonary Fibrosis
- Allergic aspergillosis (an allergic lung reaction to fungus)
- Bronchial obstruction such as inhalation of foreign objects, tumour, airway compression
- Inflammatory bowel disease
Secondary bronchiectasis is more common and may occur as a complication of other lung diseases as a consequence of airway distortion, traction and ultimate damage in relation to conditions including:
- Interstitial Lung disease