Every day, once a day, for about 7-8 months i have to cough or hack up a thick mucus plug. otherwise it obstructs airway. should i see a doctor?

Yes: You could have BRONCHIECTASIS... an isolated segment of your lung which gets plugged with your ordinary secretions . Since these segments can get infected (PNEUMONIA!!) they should be evaluated! See your PCP (Primary Care Provider) for an initial eval and possible referral Hope this helps Dr Z

Yes: This is not normal, see a pulmonologist or atleast your PCP.