I have CF and had a right pneumonectomy in 2003. At that time my left lung was in almost perfect shape, meaning I had never got pneumonia in that lung and no infections, my surgeon thought maybe after removing my bad lung (which was only doing less than 10% of the work) that I may not have any CF symptoms. He had never seen a case like mine, which had one good and one bad lung. In 2006 I started having trouble breathing and it turns out I had post pneumonectomy, which is when your chest cavity doesn't fill up will fluid, so things started shifting over, like my heart and putting pressure on my bronchial tubes making it very hard to breathe. Had another operation to put two saline implants in where the right lung was and shift everything back over. My FEV1 has been 54-56% for about the last 15 years. Another thing that has happened in the last 3-4 years is my left upper lobe has started to expand over toward my right side. My Doctor thinks that may be why I have over 50% in the one lung still.