What is vital capacity and its importance?

Vital capacity (VC) is the maximum amount of air a person can expel from the lungs after a maximum inspiration. It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume i.e, VC = IRV + TV + ERV.

The breathing capacity of the lungs expressed as the number of cubic inches or cubic centimeters of air that can be forcibly exhaled after a full inspiration. It is about 3.5 – 4.5 liters in the human body.

It promotes the act of supplying fresh air and getting rid of foul air, thereby increasing the gaseous exchange between the tissues and the environment. Thus, the greater the VC, the more is the energy available to the body. VC of a person gives important clues for diagnosing a lung problem.

Its measurement helps the doctor to decide about the possible causes of the diseases and about the line of treatment.

It determines the stamina of sportsperson and mountain climbers. Sportsperson and mountain dwellers have a higher vital capacity. Young persons have more vital capacity than aged.