I work in a icu, ex smoker, had cough history past 3 months onwards and treatment had taken , pft, montex showed normal. still cough on morning?

Cough: If your cough is quite persistent, further evaluation is recommended. It may be an asthmatic cough or due to GERD. A chest CT scan and evaluation by a pulmonologist is recommended.

Cough: Since I do NOT know your age, how long and how heavily you smoked in the past and you have had this cough for three months, I suggest you see a good lung specialist. You may need a bronchoscopy

So many causes: A chronic cough can have so many causes. Some things to think about: could it be from GERD (acid rises into your esophagus and spills into lungs causing a cough..sometimes worse when recumbent), allergies (do you sneeze, have itchy eyes?) By montex, you mean mantoux? for TB exposure? working in ICU that's important After 3 months and no better, I'd suggest a chest xray. And if that's normal, CT

See Below: The top 3 causes of chronic cough are in order, post nasal drip>asthma>acid reflux which may be silent. That and an ACE inhibitor cough account for 90ish percent of all chronic cough. Given smoking history I absolutely agree with getting a chest x-Ray. If all of these are not problems and x-Ray is normal consider high res CT.