FEV1 (forced expiratory volume in one second) is a spirometry measure indicating the volume of air exhaled in the first second of a forced breath. It quantifies airway obstruction and is central to staging COPD and asthma. Underwriters use absolute values and percent-predicted to evaluate respiratory risk, especially with smoking history or dyspnea.

For COPD or asthma histories, advisors obtain spirometry with FEV1 and percent-predicted values. Stable results and nonsmoking status support better classes. Significant obstruction often yields ratings or postponement. Coordinating pulmonary records up front reduces underwriting delays and repeat testing.