Beta-blockers are also used in eye drops for glaucoma and other eye problems. Beta-blocker eye drops can precipitate asthma symptoms, including cough. Confirmation of the diagnosis of cough-variant asthma may include a breathing test called a methacholine bronchial challenge test. GERD is the third most common cause of chronic cough. The diagnosis may be obtained from the medical history alone.
Patients often present with classic symptoms of frequent heartburn or sour taste in the mouth.
If these symptoms are present, therapy directed at GERD is initiated to resolve the cough. Forty percent of patients with GERD do not present with the classic symptoms. These patients may complain only of cough. If the pH in the esophagus falls below a certain level, acid is refluxing from the stomach. Alternatively, therapy directed at reflux can be given as a diagnostic test.