How to use a peak flow meter to monitor your asthma or COPD

A peak flow meter is a handheld device that measures airflow rate and can help those with respiratory conditions like asthma ...
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PEFR: What to Know

A peak expiratory flow rate (PEFR) measures how effectively you exhale. Also called a peak flow meter, this handheld device helps you document the amount of air and the speed at which you can ...