A friend is coughing over 3years.doctors find nothing.he is overall healthy, lungs clear.he throw up 2x per week cos of it.what could it be? worried.

Reflux: If the lung evaluation is negative and the patient is having episodes of vomiting, i would recommend looking into the prospect that this could be reflux. Perhaps, your friend is irritating his esophagus all the way up to his sinuses with the vomiting and has a form of chronic reflux bronchitis. I would use a ppi medication to acid suppress and consider a GI evaluation for possible endoscopy.