What are doctors looking for when they do a chest x-ray after a prolonged cough?

CXR & cough: Most of the time nothing. We want to rule out a possible underlying lung disease process. When the chest x-ray is negative (benign), it helps narrow the differential diagnosis (the possibilities).

Cause for cough: A structural abnormality such as bronchiectais, dilated bronchi or chronic infection. Sometimes asthma results in chronic cough. Any abnormal density on chest radiograph to explain cough. Sometimes tumors can elicit a chronic cough.