I HAVE BEEN COUGHING FOR ABOUT 6 MONTHS AND THE

I HAVE BEEN COUGHING FOR ABOUT 6 MONTHS AND THE LAST 3 MTHS I NOTICED THE FLEM was interfering with my voice, I cough the thick flem up and I am ok till next build up. I AM GOING TO TRY UPDRAFTS NEXT. I AM VERY PUZZELED AS TO WHAT IS CAUSING THIS? MY EMAIL IS YYYY@YYYY .