Patient Education

Heart Health Library

Our Health Library does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their heart health. Our providers may not see and/or treat all topics found herein.

Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein.

Peak expiratory flow

Peak expiratory flow (PEF) is a measure of how much air a person can exhale while breathing out as hard and fast as possible. PEF is used to evaluate the condition of the airways in people who have asthma or other conditions that affect their ability to breathe.

When the airways become narrowed because of inflammation or disease, the peak expiratory flow drops. Even before symptoms of asthma occur, a decrease in the peak rate can show that the bronchial tubes have narrowed.

Peak expiratory flow may be measured at home using an inexpensive device called a peak flow meter. Or it may be measured in a doctor's office using a spirometer.

Current as of: July 31, 2024

Author: Ignite Healthwise, LLC Staff

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All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.