Percent predicted forced expiratory volume (ppFEV1)

A measure showing how well a person’s lungs work.

This is a way of checking how well the lungs work. The person blows out the air in their lungs hard, fast and for as long as possible. The test measures how much air comes out of the lungs in the first second. This is the forced expiratory volume in one second (FEV1). The doctor or nurse then compares the FEV1 to the expected FEV1 for the person’s height, gender, and age. This gives the percentage predicted FEV1 (ppFEV1). This should be close to 100% when the lungs are working properly.

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