My dad recently had some tests done, and was told that he had an enlarged lymph node in his upper left lung. The Dr. said that it was, "Nothing, and come back to have it rechecked in 6 months". I am concerned that if it is something serious, isn't 6 months too long to wait? Also, what could this be a sign of?. He is 76 years old, and has been very active, good stamina for man of his age. For that last year or so, he has had a constant small cough, and gets out of breath easily. I am worried, that it could be lung cancer, and waiting 6 months could make it harder to fight if so. Thank you.