When the most common viral testing is negative, and coughing continues despite over-the-counter remedies or medical interventions, testing may include a broader viral and bacterial panel and different testing methods. Further, medical professionals may order chest radiographs, lung function testing, allergy testing, echocardiogram (heart ultrasound), and cardiac stress test, among other tests, to help determine the underlying cause of a cough. When the most common viral testing is negative, and coughing continues despite over-the-counter remedies or medical interventions, testing may include a broader viral and bacterial panel and different testing methods. Further, medical professionals may order chest radiographs, lung function testing, allergy testing, echocardiogram (heart ultrasound), and cardiac stress test, among other tests, to help determine the underlying cause of a cough.