What is the normal range for FEV1/FVC ratio in healthy individuals?

• A. 40-60%
• B. 60-70%
• C. 70-90%
• D. 90-100%

Answer: (C)

The FEV1/FVC ratio is an important diagnostic tool used in pulmonary function testing to assess lung function. FEV1, or forced expiratory volume in one second, measures how much air a person can forcibly exhale in the first second of a breath, while FVC, or forced vital capacity, measures the total amount of air expelled during the forced breath.

In healthy individuals, the normal FEV1/FVC ratio ranges from approximately 70% to 80%, making the choice of 70-90% the most accurate answer. This ratio reflects the efficiency of air flow out of the lungs. A higher ratio can indicate healthy lung function, while a lower ratio may suggest obstructive lung diseases, such as asthma or COPD. Therefore, understanding this ratio is vital in assessing respiratory health.

The values outside of this range—such as the lower percentages or those reaching 90% and above—would typically indicate either restrictive patterns or could signal other pathologies that deviate from average lung function.