question: I had surgery to remove lymph nodes from under my right arm due to breast cancer.  After that surgery I got very sick and my chest filled up with phlem. A month later I started radiation therapy.  I took radiation for about a month and a half.  during radiation treatment I always had a cough accompany by mucus.  Its been a month since I finish my radiation therapy and I don't cough that much, but my sinus continues to drain into my system and at night I feel a very small pressure in my chest.  I don't cough that much anymore but there is still mucus in my chest.  should i worry