Serious Health Question?

My dad has had this chronic cough for about 8 months now. He is about 70 pounds overweight, drinks too much beer, smokes, and eats awfully. I know you can't give me a diagnosis, but what do you think this cough could indicate? I'm looking to print some things out for him to read so that it will motivate him to lose weight, stop smoking and drinking so much and eat better. I know he has high cholesteral, he snores very loudly and his feet hurt a lot. An idea of a major problem (heart disease/lung cancer/etc.) that he could potentially have or get would be very helpful so that I could help him get on a new track. Thanks!