Bronchiectasis can develop at any age but begins most often in early childhood. The condition usually affects young people more frequently than adults.
The majority of bronchiectasis is acquired, which means there has been direct damage or destruction to the bronchial walls. This can be the result of infection, inhalation of toxic chemicals, or damage from another lung condition.
Many cases of bronchiectasis begin with pneumonia due to viruses such as influenza and measles, or bacteria such as whooping cough or tuberculosis.
A person may have no obvious symptoms for many years and then sometimes, after a respiratory infection, symptoms start and gradually worsen.
Once a person has bronchiectasis they usually have it for life, though there is some evidence that it is possible to stop the disease getting worse − or even reverse it − in children.