Emphysema is a progressive lung disease that results in shortness of breath and a reduced capacity for physical activity. It is caused by inflammation within the small air sacs and small airways of the lungs, which can lead to the destruction of the air sac walls and eventually to airway collapse. Treatment options for emphysema include both non-surgical and surgical interventions. Pulmonary rehabilitation, a non-surgical treatment, includes a combination of education, exercise training, nutrition advice, and smoking cessation programs. The goal of pulmonary rehabilitation is to increase exercise tolerance and reduce breathing difficulties. Two surgical treatment options include lung volume reduction surgery, in which small amounts of damaged lung tissue are removed, and lung transplantation, in which a person's damaged lung is replaced with a healthy lung from a donor. While these surgical options may offer potential improvements in quality of life, they also impose substantial risks, including infections, pneumonia, or even death. In this study, researchers will follow participants over a long period of time to assess the effects of pulmonary rehabilitation, lung volume reduction surgery, and lung transplantation on health outcomes and quality of life.