Measuring Lung Function

Tools and Tests for Assessing Respiratory Health

Healthcare professionals use several tools to evaluate how well your lungs are working. Understanding these tests can help you communicate with your doctor and track your own respiratory health over time.

Spirometry

Spirometry is the most common pulmonary function test. You breathe into a device called a spirometer, which measures how much air you can inhale and exhale and how quickly you can blow air out. Key measurements include:

FVC (Forced Vital Capacity): The total amount of air you can forcefully exhale after a full breath.

FEV1 (Forced Expiratory Volume in one second): The amount of air you can forcefully exhale in the first second. A reduced FEV1/FVC ratio may indicate obstructive lung disease.

Peak Flow Measurement

A peak flow meter is a portable device that measures the fastest rate at which you can blow air out of your lungs. People with asthma often use peak flow meters at home to monitor their condition and detect early signs of worsening airflow obstruction.

Pulse Oximetry

A pulse oximeter is a small, clip-like device placed on a fingertip that measures blood oxygen saturation (SpO2). Normal readings are typically between 95% and 100%. Consistently low readings may indicate a problem with gas exchange and should be discussed with a healthcare provider.