Definition and Overview
Spirometry Versus Full Pulmonary Function Tests
Pulmonary function tests are a method of assessing the function of the lungs. They are a way of detecting and quantifying abnormal lung function in a noninvasive manner. They are one of the most common diagnostic tests used for measuring lung function. The simplest form of pulmonary function testing is called spirometry which measures how quickly air can be expelled from the lungs. Spirometry is performed by having an individual blow into a device called a spirometer. This machine makes tracings of the rate at which air leaves the lungs. That is, it measures the volume of air that is inhaled or exhaled as a function of time. Spirometry is most useful for measuring diseases that cause obstruction to airflow. Spirometry is unable to measure absolute lung volumes. That is, it does not measure the amount of air in the lungs, just the amount of air entering or leaving the lungs.