Bronchiectasis

 

About bronchiectasis

Bronchiectasis is a long-term condition where the airways of the lungs become abnormally widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection.

The most common symptoms of bronchiectasis include:

• a persistent cough that usually brings up phlegm (sputum)
• breathlessness

The severity of symptoms can vary widely. Some people have only a few symptoms that don't appear often, while others have wide-ranging daily symptoms.

The symptoms tend to get worse if you develop an infection in your lungs.

How the lungs are affected

The lungs are full of tiny branching airways, known as bronchi. Oxygen travels through these airways, ends up in tiny sacs called alveoli, and from there is absorbed into the bloodstream.

The inside walls of the bronchi are coated with sticky mucus, which protects against damage from particles moving down into the lungs.

In bronchiectasis, one or more of the bronchi are abnormally widened. This means more mucus than usual gathers there, which makes the bronchi more vulnerable to infection. If an infection does develop, the bronchi may be damaged again, so even more mucus gathers in them, and the risk of infection increases further.

Over time, this cycle can cause gradually worsening damage to the lungs.

Why it happens

Bronchiectasis can develop if the tissue and muscles that surround the bronchi are damaged or destroyed. 

There are many reasons why this may happen. The three most common causes  are:

• a lung infection during childhood, such as pneumonia, whooping cough, that damages the bronchi
• underlying problems with the immune system (the body’s defence against infection) that make the bronchi more vulnerable to damage from an infection
• allergic bronchopulmonary aspergillosis (ABPA) – an allergy to a certain type of fungi that can cause the bronchi to become inflamed if spores from the fungi are inhaled