A. The next step would be a thorough cardiac exam, as congestive heart failure can cause persistent coughing (pulmonary edema). Also radiographs would be helpful as the lungs can be evaluated as well as the heart. You may also check the relative humidity in your house and use a humidifier, if the air is very dry. Sometimes very dry air (e.g when you live in the mountains in Arizona or New Mexico, and many other states) can cause persistent coughing.
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