hello. I am 29 years old and have a about a 3 pack year history (about 7 cigarettes per day for the past 8 years). I am trying to quit smoking but it has been very difficult. Today is my new "quit day" so I am giving it another shot. My problem is i have a persistent chest pain only on my right side. The sypmtoms worsen when I smoke. The pain is not always there, I have days with no pain and then other days with chest pain. The pain is dull and nagging and is not extreme. My other symptom is i cough up little brown spots on a daily basis. There is never any blood in it though. My doctor attributes the problems to acid reflux and has diagnosed me with acid reflux and i had an endoscopy done which further suggested i have an acid reflux problem, but the acid reflux medication is not effective. I stress out all the time about the possibility of lung cancer. I have had the chest pain and brown spots in my sputum for about 2 years. I had a chest x-ray 2 years ago which showed no problems and I had a ct scan one year ago which showed no problems. I have no other symptoms and have no problems with wheezing and I am able to exercise (basketball, running, etc.) without any problems. Could this be lung cancer. Is that likely. What should i do to rule out lung cancer