Peak flow meters are devices used to measure how well air is moving through your lungs. This brochure presents some general steps for how to use a peak flow meter.
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How to Use a Peak Flow Meter
Peak flow meters are devices used to measure how well air is moving through your lungs.
Here are some general steps for how to use a peak flow meter. Be sure to read the instructions that come with your peak flow meter. Ask your doctor, pharmacist, or other health care professional (such as nurse practitioner, physician assistant, nurse, respiratory therapist, or asthma educator) to show you how to use your peak flow meter. Review your technique at each follow-up visit. This page also tells you what the numbers on the meter mean and how they can help you and your doctor or other health care professional keep your asthma under control.
Compare the highest number with the peak flow numbers on your written asthma action plan. Check to see which zone the number falls under and follow the plan's instructions for that zone.
GREEN ZONE: 80% - 100% of personal best -- Take daily long-term control medication, if prescribed
YELLOW ZONE: 50% - 79% of personal best -- Add quick-relief medication(s) as directed and continue daily long-term control medication, if prescribed. Continue to monitor.
RED ZONE: Less than 50% of personal best -- Add quick-relief medication(s) as directed. Get medical help now.
How to Find Your Personal Best or Usual Peak Flow
Your doctor or other health care professional may also want you to take your peak flow before and after using your quick-relief medicine. Follow his or her instructions.
Find a new personal best with each new peak flow meter (different meters can give different numbers).
Find a new personal best for children every 6 months to allow for growth changes.
Source: National Heart, Lung, and Blood Institute; National Institutes of Health; U.S. Department of Health and Human Services.