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How to measure peak flow

How to measure peak flow
  • Move the marker to the bottom of the numbered scale.
  • Stand up straight.
  • Take a deep breath. Fill your lungs all the way.
  • Hold your breath while you place the mouthpiece in your mouth, between your teeth. Close your lips around it. Do not put your tongue inside the hole.
  • Blow out as hard and fast as you can in a single blow. Your first burst of air is the most important, so blowing for a longer time will not affect your result.
  • Write down the number you get. If you coughed or did not do the steps right, do not write down the number. Do it over again.
  • Move the marker back to the bottom and repeat these steps 2 more times. The highest of the 3 numbers is your peak flow number. Write it down in your results log.

Update Date: 4/26/2010

Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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