WebMD
Font Size
A
A
A

Peak Flow Meter

A peak flow meter is an inexpensive, pocket-sized device that measures peak expiratory flow (PEF), or how much air a person can exhale. To measure PEF, the person takes a deep breath and then blows (huffs) into a tube on the peak flow meter as hard and as fast as possible.

To get the most accurate PEF, the peak flow meter should be used three times and the best results recorded. PEF is lowest in the early morning and highest in the afternoon.

Results obtained by using a peak flow meter are not as accurate as those obtained by using spirometry, another test used to measure lung function. But the peak flow meter can be used at home, while spirometry has to be done in a doctor's office.

By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Rohit K Katial, MD - Allergy and Immunology
Current as of February 22, 2013

WebMD Medical Reference from Healthwise

Last Updated: February 22, 2013
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.