In pulmonary function tests, what does FEV1 measure?

FEV1, or Forced Expiratory Volume in one second, specifically measures the volume of air that can be forcibly exhaled in the first second of a complete expiratory maneuver following a maximal inhalation. This measurement is crucial in assessing lung function and is particularly valuable in diagnosing and monitoring obstructive and restrictive lung diseases. Higher FEV1 values typically indicate better lung function, while lower values can indicate airway obstruction, which is commonly seen in conditions like asthma and COPD (Chronic Obstructive Pulmonary Disease).

The significance of FEV1 lies in its ability to provide insight into the patient's ability to expel air from their lungs quickly, which is essential for evaluating respiratory health. FEV1 is often used in conjunction with other parameters, such as FVC (Forced Vital Capacity), to calculate the FEV1/FVC ratio, which helps further delineate obstructive versus restrictive patterns in lung disease. Understanding its role is vital for respiratory therapists and clinicians in creating effective treatment plans and monitoring patient progress.