I don't have copd but have known people who do. The below link actually says it all. I don't know what stage you are in, but if you didn't even know you had it perhaps it is in the early stages.

If you have lots of stress I am sure that your doctor could help you with a program to quit smoking. It is hard to quit and you mail fail many times before you suceed. Good Luck

http://www.e-copd.com/COPD_Stages.html