Making the Diagnosis
A doctor may suspect bronchiectasis because of symptoms, or because a person has a condition related to it. X-rays can lead to the diagnosis and show the location and extent of the damage, but sometimes bronchiectasis is not revealed on regular X-rays. Bronchiectasis can usually be confirmed by high-resolution computed tomography (CT scan).
Once bronchiectasis is diagnosed, a doctor will check for diseases causing it. These tests may measure salt levels in the sweat to test for cystic fibrosis, or measure immunoglobulin levels in the blood. Samples from the nose or bronchi can show if the mucus-clearing cells are genetically defective. When bronchiectasis has affected only a small area, doctors may thread a tiny camera into the bronchi to see if a lung tumor or inhaled foreign object is the cause. This procedure is called fiber-optic bronchoscopy.
Other tests may be done to see if someone has allergic bronchopulmonary aspergillosis, a condition caused by a severe allergy to a kind of fungus. It causes a form of bronchiectasis that affects the large bronchi.