What is inspiratory reserve volume?

Inspiratory reserve volume (IRV) is the amount of air that can be forcefully inhaled after a normal tidal inspiration. It is the maximum amount of air that can be taken in during a deep breath. The average inspiratory reserve volume for healthy adults is approximately 3 liters, but it can vary depending on factors such as age, gender, and overall lung capacity. A decrease in inspiratory reserve volume can indicate underlying respiratory disorders such as chronic obstructive pulmonary disease (COPD) or emphysema. Conversely, increased inspiratory reserve volume can be indicative of strong lung function and overall respiratory health.