Catch any disease in the early stages is extremely important, and lung diseases and maladies are no different. The sooner a chronic disease or an acute illness is detected, the easier and quicker it will be treated, and the higher chance you have of living through it. Unfortunately, the signs and symptoms of the early stages of diseases like COPD and even lung cancer are usually subtle and often overlooked until the disease has progressed into the advanced stages.
Since this is often the case, it's important to consider family history of chronic diseases, so you will know to pay close attention to your physical state and to get tested for any diseases that run in your family. If you had relatives who died of lung cancer, you will need to pay special attention, and your doctor will likely order a regular screening to be done.