Smoker I've been coughing up phlegm tinged with blood at times I had a CT scan it states that their is cystic changes and a parenchymal density lung?

Parenchymal density. is a very nonspecific term, unfortunately. It could mean anything from scar to mass to pneumonia to collapse of a small lung segment. Without the images to review, it is difficult to determine. Likewise, there are both acute and chronic causes of cystic changes. The nonspecific report verbiage needs to be interpreted in conjunction with the images themselves and your clinical picture.