normal lungs

What Are The 4 Stages Of Emphysema? Stage 1 or Mild (80% of normal) Stage 2 or Moderate (50-80%) Stage 3 or Severe (30-50%) emphysema. Stage 4 or Very severe, (less than 30%), end-stage, severe or end-stage emphysema. What happens in the body during emphysema? In people with emphysema, the air sacs in the lungs