I have had problems with extended chronic coughing in the past couple years. According to my doctor chronic coughing is typically caused by:
- post nasal drip
- acid reflux
Unfortunately, I found out I have all of the above (with my reflux having coughing as the main symptom) and it took a very long time to find a regimine to get them all under control at the same time.
I have also had pertussis. Not fun, but it eventually got better.