Hello
You are having cough with mucus ( phlegm or expectoration ) for 1 &1/2 months .
Feeling faintness when stand up , dizziness and tight chest .
All these symptoms may be due to these reasons , these include:
1 Allergic
bronchitis , as you are smokers and this causes
bronchoconstriction and this produces cough and added infection produces mucus .
So due to smoking or any other allergen you developed allergic bronchitis .
2
Bronchiectasis , may be the 2nd reason of such symptoms . If the amount of mucus produced is more than 10 ml it may be due to bronchiectasis .
3
Tuberculosis , diagnosis can be confirmed by X ray chest and sputum for a f b and blood for CBC & ESR .
As you mentioned that you are also having dizziness and faintness , so these symptoms may be due to anemia , so get in
hemoglobin examination .
Since your are having these symptoms for long time , this is the best way to consult chest physician and get his opinion.
Hope this will help you.