In emphysema, for exemple, the division betwween the alveoli break down, producing larger lung spaces. This destruction of lung tissue reduces the springiness of the lungs. The lungs becomes more compliant, a small change in pressure produces a larger than normal change in the volume. While at first glance this would appear to make it easier to breathe, the opposite is true. Much of the work of breathing is done in overcoming the resistance of the airways. In the course of different respiratory diseases, the lung diffusing capacity will evolve since different additional constituent are responsible for different diseases and can suggest that time evolution of lung diffusing capacity simplify the eary diagnostic of respiratory diseases.