The term vital capacity (VC) specifies the volume of air that can be moved into or out of the lungs in one breath; equal to the sum of the inspiratory and expiratory reserve volumes and the tidal volume.
In the psychology context, vital capacity refers to the maximum amount of air that an individual can forcefully exhale after taking a deep breath. It is a measure of lung function that is often used in the assessment of respiratory disorders, such as asthma and chronic obstructive pulmonary disease (COPD).
Vital capacity is typically measured using a spirometer, which is a device that records the volume and flow rate of air that a person inhales and exhales. During a spirometry test, a person will be asked to take a deep breath and then exhale as forcefully as possible for several seconds.
A normal vital capacity range varies based on age, gender, and other factors. Generally, vital capacity decreases with age and in individuals with respiratory disorders. In addition to assessing lung function, vital capacity can also be used to monitor changes in respiratory function over time and evaluate the effectiveness of treatments for respiratory disorders.
Examples of situations where vital capacity measurement is useful include:
- Assessing lung function in individuals with respiratory disorders such as asthma or COPD
- Monitoring the progression of respiratory disorders
- Evaluating the effectiveness of treatments for respiratory disorders
- Assessing the impact of smoking or environmental pollutants on lung function
- Measuring changes in lung function over time in individuals with chronic conditions such as cystic fibrosis