FEV1/FVC ratio

The FEV1/FVC ratio is a measure used in lung function tests to assess breathing. FEV1 (forced expiratory volume in one second) is the amount of air a person can forcefully exhale in the first second. FVC (forced vital capacity) is the total amount of air exhaled after taking a deep breath. The ratio compares these two values to see how much air can be expelled quickly versus the total air. A low ratio may indicate airflow obstruction, as seen in conditions like asthma or COPD, helping doctors diagnose and monitor lung issues.