Your father undoubtedly has chronic bronchitis, due to cigarette smoking. One can have this, without having emphysema and/or the signs of obstruction to air flow. He probably does have signs of emphysema, on the CT scan. Emphysema is destruction of lung, usually but not always associated with blockage to air flow that causes shortness of breath and that may be the reason that he is able to exercise without shortness of breath.
Advanced usually is synonymous with severe. It implies that the disease process has been progressive for a long time. What your father should seek is clarification of his diagnosis and the CT scan findings, by a lung specialist, also known as a pulmonologist, who will surely order complete pulmonary function tests (PFTs), a more accurate way, or at least a different way, to assess the severity of his lung condition than the CT scan.
What is unequivocal is that your father must stop smoking immediately, if he wants to have any chance of preserving his lung function. He should do this with your strong encouragement, with the help of his doctor and prescription of nicotine replacement therapy along with at least one other smoking cessation medicine such as Wellbutrin® (buproprion) or Chantix® (varenicline), counseling and group support, both at home and in his workplace.
This is a critical moment for your father. Should he opt to continue smoking, it will almost certainly shorten his life expectancy, worsen his cough and probably make it permanent and bring on shortness of breath, initially with exertion and ultimately while at rest – the quality of his life will decline precipitously. As they say, this is a death-defying decision.
Good luck.
I taught rehabilitation to people just like your father in law for 10 years after spending 12 years working in intensive care, watching the end result of the disease process.
I hope your father in law is truely ready to make some positive changes. When his oxygen level drops low enough (due to damaged lung tissue) the results will be noticed in eye sight, short term memory and fatigue. The low oxygen levels will result in heart failure. This disease process involves progressive weakening of the heart muscle. Nothing comes with ease at that point.
I hope he will come by my blog, Heart Failure Solutions, and read every article in the oxygen category. I am in the process of adding a forum to my site, so we hope to offer more interaction soon. If you have any questions, just leave a comment.
Many blessings.
PS- Sometimes the hardest thing to do is to watch our loved ones make bad choices. The only thing you can do is offer help and support. Education is the best health building tool.