A physical exam and diagnostic testing can reveal more clues. A doctor will look at the lungs, for example, for signs of asthma or structural problems such as emphysema or lung cancer. A look at the stomach can confirm GERD, while the sinuses reveal signs of postnasal drip. Other tests that help decide how to treat a cough include pulmonary function testing (to measure how well lungs work), a chest X-ray, a CT scan, and an endoscopy (to examine nasal passages, bronchial tubes, or the esophagus). Often, more than one condition is causing a cough.
The good news: Doctors can pinpoint the problem(s) in the vast majority of cases.
