Definition: Expiratory reserve volume (ERV) refers to the extra volume of air that can be exhaled with maximum effort beyond the level reached at the end of a normal, passive exhalation.
If you have breathing difficulties, your doctor may run several tests to get measurements that can help determine the severity of your condition. One of those measurements is expiratory reserve volume.
ERV is measured during lung volume measurements.
Also Known As: ERV, reserve air, supplemental air
