Why is vital capacity of the lungs an important indicator of health?

The lungs are a very important organ of animals and humans in particular. All due to the fact that this organ provides gas exchange. It is in the lungs that the capillaries are located through which the red blood cells are saturated with oxygen. If the lungs have a small volume, they are weak, one lung is missing (which happens when removed during an operation in case of illness), then the body begins to suffer from a lack of oxygen. Oxygen enters the organs, but often in insufficient quantities, especially when doing hard work. Therefore, lung health is an indicator of overall health.