Help with symptoms

I'm 26 years old and have a 10 year smoking history, smoking on average 5-7 cigs. a day. Recently, I have experienced a feeling which I would describe as a "heaviness" in my chest. It is not painful and I am not experiencing breathing difficulties. I do have an infrequent, non-productive cough. I'm also experiencing occasional pain around the area of my shoulder blade. I experienced such pain about a year and a half ago as well and consequently had a chest x-ray (was experiencing some chest pain as well) which came out as normal. With the onset of this chest heaviness, I have experienced fatigue, dizziness and an inability to concentrate. Are these symptoms consistent with lung cancer or more with something like depression and/or anxiety? I understand that this is not necessarily a forum for diagnosis but I would appreciate any insight readers might have, especially since it appears that many of you are much more knowledgeable about these matters than I. Thanking you in advance for your help.

MRP

P.S. - I don't know if this is relevant but I engaged in 30 mins of fairly intense cardio activity (treadmill) 2 days ago w/no real difficulty.

[National Jewish]

As you suggest, symptoms such as chest heaviness and/or pain often occur with anxiety.  This can happen with or without panic attacks.  They are not symptoms usually seen with lung cancer.  A recent normal chest x-ray would eliminate that concern.  Your ability to engage in rather intense aerobic exercise is encouraging.  This suggests good heart and lung function.

Fatigue, dizziness and an inability to concentrate could also be due to anxiety but these can be symptoms of many other health problems.  A thorough physical exam and blood testing is the best way to have this checked out.