Depends: .. on which test were done? Potential causes of persistent cough are too many to discuss here. Medication side effect is often overlooked. Persistent post nasal drip (allergy or non-allergy related), acid reflux, asthma, or vocal cord lesion are common causes that may occur with normal lab results (if not "looking" in the right direction).
Answered 4/8/2015
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A doctor has provided 1 answer
A doctor has provided 1 answer
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