View All. Symptoms of emphysema are insidious in nature and may not, at first, be easy to recognize. Emphysema is among a group of lung diseases known as COPD, in which the alveoli of the lungs become damaged, causing them to enlarge and burst. Because the alveoli are where oxygen and carbon dioxide are exchanged, damage to this area makes it difficult for people with emphysema to expel all their air. This causes a build-up of carbon dioxide in the body.