This condition can happen in different ways as a result of many different problems, all of which attack the bronchial wall by interfering with its defence system. Many medical conditions cause bronchiectasis. The most common cause is chronic or recurring infection. These infections may be caused by things such as immune system problems, birth defects affecting the structure or function of the airways, and blocked airways. A small number of cases result from breathing in toxic substances that hurt the bronchi.
The following is a list of some of the infections and conditions that can cause bronchiectasis.
- whooping cough
- viral infection
- bacterial infection
- fungal infection
- mycoplasma infection
Causes of blocked airways:
- lung tumour
- enlarged lymph glands
- inhaled foreign object
- cystic fibrosis
- ciliary dyskinesia, including Kartagener's syndrome
- alpha-1-antitrypsin deficiency
- immunoglobulin deficiency syndromes
- white blood cell problems
- autoimmune or hyperimmune disorders (rheumatoid arthritis, ulcerative colitis)
- toxic fumes, gases, or particles
- inhaling food or stomach acid
- HIV infection
- drug abuse, such as heroin use
Normally, the bronchial wall contains cells that protect the airways and lungs from harmful substances. Some of these cells produce mucus to trap foreign objects, while others remove the mucus from the airways.
In bronchiectasis, the bronchial wall becomes chronically inflamed or is destroyed. When this happens, the cells that clear the mucus can be hurt or killed. A mucus buildup then takes place that may further damage the bronchial wall and spread infection. The increased mucus may also allow bacteria to grow that can block the lung's large airways (the bronchus) and lead to low oxygen levels in the blood.
At the same time, the inflammation of the bronchi (plural of bronchus) may also spread to the small air sacs of the lungs (alveoli). If this happens, pneumonia can develop and result in scarring and a loss of lung tissue. In severe cases, scarring and a loss of blood vessels in the lungs may strain your heart.